How to add additional tag for EBS volume base on variable?

I’m using this EC2 module with lite alteration to create EC2 instances and EBS volumes, Code is working without an issue, But I have requirement to add mount point as a tag in EBS, So I can use data filter to get that value and mount it using Ansible. Im trying to add tag value to "dynamic “ebs_block_device” through depoy-ec2.tf configuration file. As per the Terraform documentation tags is an optional value. Anyway, when I executing this it provided Unsupported argument error for tags value. Appreciate your support to understand issue here.

locals {
  is_t_instance_type = replace(var.instance_type, "/^t(2|3|3a){1}\\..*$/", "1") == "1" ? true : false
}

resource "aws_instance" "this" {
  count = var.instance_count

  ami              = var.ami
  instance_type    = var.instance_type
  user_data        = var.user_data
  user_data_base64 = var.user_data_base64
  subnet_id = length(var.network_interface) > 0 ? null : element(
    distinct(compact(concat([var.subnet_id], var.subnet_ids))),
    count.index,
  )
  key_name               = var.key_name
  monitoring             = var.monitoring
  get_password_data      = var.get_password_data
  vpc_security_group_ids = var.vpc_security_group_ids
  iam_instance_profile   = var.iam_instance_profile

  associate_public_ip_address = var.associate_public_ip_address
  private_ip                  = length(var.private_ips) > 0 ? element(var.private_ips, count.index) : var.private_ip
  ipv6_address_count          = var.ipv6_address_count
  ipv6_addresses              = var.ipv6_addresses

  ebs_optimized = var.ebs_optimized

  dynamic "root_block_device" {
    for_each = var.root_block_device
    content {
      delete_on_termination = lookup(root_block_device.value, "delete_on_termination", null)
      encrypted             = lookup(root_block_device.value, "encrypted", null)
      iops                  = lookup(root_block_device.value, "iops", null)
      kms_key_id            = lookup(root_block_device.value, "kms_key_id", null)
      volume_size           = lookup(root_block_device.value, "volume_size", null)
      volume_type           = lookup(root_block_device.value, "volume_type", null)
    }
  }

  dynamic "ebs_block_device" {
    for_each = var.ebs_block_device
    content {
      delete_on_termination = lookup(ebs_block_device.value, "delete_on_termination", null)
      device_name           = ebs_block_device.value.device_name
      encrypted             = lookup(ebs_block_device.value, "encrypted", null)
      iops                  = lookup(ebs_block_device.value, "iops", null)
      kms_key_id            = lookup(ebs_block_device.value, "kms_key_id", null)
      snapshot_id           = lookup(ebs_block_device.value, "snapshot_id", null)
      volume_size           = lookup(ebs_block_device.value, "volume_size", null)
      volume_type           = lookup(ebs_block_device.value, "volume_type", null)
      tags                  = lookup(ebs_block_device.value, "mount", null)
      
    }
  }

  dynamic "ephemeral_block_device" {
    for_each = var.ephemeral_block_device
    content {
      device_name  = ephemeral_block_device.value.device_name
      no_device    = lookup(ephemeral_block_device.value, "no_device", null)
      virtual_name = lookup(ephemeral_block_device.value, "virtual_name", null)
    }
  }

  dynamic "metadata_options" {
    for_each = length(keys(var.metadata_options)) == 0 ? [] : [var.metadata_options]
    content {
      http_endpoint               = lookup(metadata_options.value, "http_endpoint", "enabled")
      http_tokens                 = lookup(metadata_options.value, "http_tokens", "optional")
      http_put_response_hop_limit = lookup(metadata_options.value, "http_put_response_hop_limit", "1")
    }
  }

  dynamic "network_interface" {
    for_each = var.network_interface
    content {
      device_index          = network_interface.value.device_index
      network_interface_id  = lookup(network_interface.value, "network_interface_id", null)
      delete_on_termination = lookup(network_interface.value, "delete_on_termination", false)
    }
  }

  source_dest_check                    = length(var.network_interface) > 0 ? null : var.source_dest_check
  disable_api_termination              = var.disable_api_termination
  instance_initiated_shutdown_behavior = var.instance_initiated_shutdown_behavior
  placement_group                      = var.placement_group
  tenancy                              = var.tenancy

  tags = merge(
    {
      "Name" = var.instance_count > 1 || var.use_num_suffix ? format("%s${var.num_suffix_format}-EC2", var.name, count.index + 1) : format("%s-EC2",var.name)
    },
    {
      "ResourceName" = var.instance_count > 1 || var.use_num_suffix ? format("%s${var.num_suffix_format}-EC2", var.name, count.index + 1) : format("%s-EC2",var.name)
    },
    {"Account" = var.Account,
    "Environment" = var.Environment, 
    "ApplicationName" = var.ApplicationName,
    "ApplicationID" = var.ApplicationID,
    "Project" = var.Project,
    "ProjectCode" = var.ProjectCode,
    "Workload" = var.Workload, 
    "Division" = var.Division, 
    "Purpose" = var.Purpose, 
    "VersionNumber" = var.VersionNumber, 
    "RelVersion" = var.RelVersion, 
    "OSVersion" = var.OSVersion, 
    "DBVersion" = var.DBVersion,
    "DataClassification" = var.DataClassification,
    "Automation" = var.Automation,
    "AWSResoureceType" = "EC2",
    "BusinessEntitiy" = var.BusinessEntitiy,
    "CostCentre" = var.CostCentre,
    "BaseImageName" = var.BaseImageName},
    var.tags,
  )

  volume_tags = merge(
    {
      "Name" = var.instance_count > 1 || var.use_num_suffix ? format("%s${var.num_suffix_format}-EBS", var.name, count.index + 1) : format("%s-EBS",var.name)
    },
    {
      "ResourceName" = var.instance_count > 1 || var.use_num_suffix ? format("%s${var.num_suffix_format}-EBS", var.name, count.index + 1) : format("%s-EBS",var.name)
    },
    
    {"Account" = var.Account,
    "Environment" = var.Environment,
    "ApplicationName" = var.ApplicationName,
    "ApplicationID" = var.ApplicationID,
    "Project" = var.Project,
    "ProjectCode" = var.ProjectCode,
    "Workload" = var.Workload,
    "Division" = var.Division,
    "Purpose" = var.Purpose,
    "VersionNumber" = var.VersionNumber,
    "RelVersion" = var.RelVersion,
    "OSVersion" = var.OSVersion,
    "DBVersion" = var.DBVersion,
    "DataClassification" = var.DataClassification,
    "Automation" = var.Automation,
    "AWSResoureceType" = "EC2",
    "BusinessEntitiy" = var.BusinessEntitiy,
    "CostCentre" = var.CostCentre,
    "BaseImageName" = var.BaseImageName},
    var.volume_tags,
  )

  credit_specification {
    cpu_credits = local.is_t_instance_type ? var.cpu_credits : null
  }
}
module "mn-ec2" {
    source = "../../../terraform12-modules/aws/ec2-instance"

    instance_count = var.master_nodes

    name                        = "${var.Account}-${var.Environment}-${var.ApplicationName}-${var.Project}-${var.Division}-${var.Purpose}-MN"
    ami                         = var.ami_id
    instance_type               = var.master_node_ec2_type
    subnet_ids                   = ["${data.aws_subnet.primary_subnet.id}","${data.aws_subnet.secondory_subnet.id}","${data.aws_subnet.tertiary_subnet.id}"]
    vpc_security_group_ids      = ["${module.sg-application-servers.this_security_group_id}"]
    iam_instance_profile        = "${var.iam_instance_profile}"
    key_name                    = var.key_pair_1
    
    Project                     = upper(var.Project)
    Account                     = var.Account
    Environment                 = var.Environment
    ApplicationName             = var.ApplicationName
    ApplicationID               = var.ApplicationID
    ProjectCode                 = var.ProjectCode
    Workload                    = var.Workload
    Division                    = var.Division
    RelVersion                  = var.RelVersion
    Purpose                     = var.Purpose
    DataClassification          = var.DataClassification
    CostCentre                  = var.CostCentre
    Automation                  = var.Automation
    tags = {
        node_type = "master"
    }
    volume_tags = {
        node_type = "master"
    }

    root_block_device = [
        {
        encrypted = true
        kms_key_id = var.kms_key_id
        volume_type = "gp2"
        volume_size = 250
        },
    ]
    ebs_block_device = [
        {
        device_name = "/dev/sdc"
        encrypted = true
        kms_key_id = var.kms_key_id
        volume_type = "gp2"
        volume_size = 500
        mount = "/x02"            
        },
        {
        device_name = "/dev/sdd"
        encrypted = true
        kms_key_id = var.kms_key_id
        volume_type = "gp2"
        volume_size = 1000
        mount = "/x03"            
        },
        {
        device_name = "/dev/sde"
        encrypted = true
        kms_key_id = var.kms_key_id
        volume_type = "gp2"
        volume_size = 10000
        mount = "/x04"            
        },

    ]
}