Error in Block Dynamic with For_each and For - Provider Azure

Hello Friends, please, I would like to ask if a situation like mine has already happened.

In the context of Azure Application Gateway, I need my Dynamic tile to access a list within an object that is within that object there is another list of objects. It sounds complex, but, for example, it would be in the case of a single call creating multiple “backend_http_settings” within a Backend_Address_Pool.

Terraform Version

Terraform v0.12.24
+ provider.azurerm v1.44.0
+ provider.template v2.1.2

Terraform Configuration Files

provider "azurerm" {
  version = "1.44"
  {...}
  terraform {
  required_version = ">= 0.12"
  {...}
}

Steps to Reproduce

terraform init
terraform -target="module.indices_app_gateway"

My Variable:

variable "backend_virtualmachines" {
  default = []
}

My consumption of the variable:

    module "my_application_gateway" {
    ...
    ...

         backend_virtualmachines = [
            {
              #Backend Pool
              backend_name = "<name backend address pool>"
              ip_addresses = [module.virtual_machines.load_balance_public_ip.0.ip_address]
        
              #HTTP Settings
              appg_http_settings = [
                {
                  name_http_settings = "<name_http_settings>"
                  port         = 80
                  protocol     = "Http"
                  cookie_based_affinity = "Disabled"
                  hostname     = "<hostname>"
                  request_timeout = 20
                  probe_name = ""
                  trusted_root_certificate_names = [""]
                },
                {
                  name_http_settings = "<name_https_settings>"
                  port         = 443
                  protocol     = "Http"
                  cookie_based_affinity = "Disabled"
                  hostname     = "<hostname>"
                  request_timeout = 20
                  probe_name = ""
                  trusted_root_certificate_names = ["<trusted_certificate>"]
                },
              ]
    ...
    ...

My code.tf

resource "azurerm_application_gateway" "application_gateway" {
...
...
# HTTP Settings
      dynamic "backend_http_settings" {
        for_each = length(var.backend_virtualmachines) == 0 ? [] : [for c in var.backend_virtualmachines : {
          for_each = [for xc in c.appg_http_settings : {
            name                  = xc.name_http_settings
            port                  = xc.port
            protocol              = xc.protocol
            cookie_based_affinity = xc.cookie_based_affinity
            host_name             = xc.hostname
            request_timeout       = xc.request_timeout
            probe_name            = xc.probe_name
            trusted_root_certificate_names = xc.trusted_root_certificate_names
          }]
        }]
        content {
          name                  = backend_http_settings.value.name
          port                  = backend_http_settings.value.port
          protocol              = backend_http_settings.value.protocol
          cookie_based_affinity = backend_http_settings.value.cookie_based_affinity
          host_name             = backend_http_settings.value.host_name
          affinity_cookie_name  = "ApplicationGatewayAffinity"
          request_timeout       = backend_http_settings.value.request_timeout
          probe_name            = backend_http_settings.value.probe_name
          trusted_root_certificate_names = backend_http_settings.value.trusted_root_certificate_names
        }
    ...
    ...

Terraform Crash

!!!!!!!!!!!!!!!!!!!!!!!!!!! TERRAFORM CRASH !!!!!!!!!!!!!!!!!!!!!!!!!!!!

Terraform crashed! This is always indicative of a bug within Terraform.
A crash log has been placed at "crash.log" relative to your current
working directory. It would be immensely helpful if you could please
report the crash with Terraform[1] so that we can fix this.

When reporting bugs, please include your terraform version. That
information is available on the first line of crash.log. You can also
get it by running 'terraform --version' on the command line.

SECURITY WARNING: the "crash.log" file that was created may contain
sensitive information that must be redacted before it is safe to share
on the issue tracker.

[1]: https://github.com/hashicorp/terraform/issues

!!!!!!!!!!!!!!!!!!!!!!!!!!! TERRAFORM CRASH !!!!!!!!!!!!!!!!!!!!!!!!!!!!

Other Code

My other code2.tf

resource "azurerm_application_gateway" "application_gateway" {
...
...

# HTTP Settings
  dynamic "backend_http_settings" {
    for_each = length(var.backend_virtualmachines) == 0 ? [] : [for c in var.backend_virtualmachines : {
      name                  = c.appg_http_settings.name_http_settings
      port                  = c.appg_http_settings.port
      protocol              = c.appg_http_settings.protocol
      cookie_based_affinity = c.appg_http_settings.cookie_based_affinity
      host_name             = c.appg_http_settings.hostname
      request_timeout       = c.appg_http_settings.request_timeout
      probe_name            = c.appg_http_settings.probe_name
      trusted_root_certificate_names = c.appg_http_settings.trusted_root_certificate_names
    }]
    content {
      name                  = backend_http_settings.value.name
      port                  = backend_http_settings.value.port
      protocol              = backend_http_settings.value.protocol
      cookie_based_affinity = backend_http_settings.value.cookie_based_affinity
      host_name             = backend_http_settings.value.host_name
      affinity_cookie_name  = "ApplicationGatewayAffinity"
      request_timeout       = backend_http_settings.value.request_timeout
      probe_name            = backend_http_settings.value.probe_name
      trusted_root_certificate_names = backend_http_settings.value.trusted_root_certificate_names
    }
...
...

Terraform Error (in code2.tf)

Error: Unsupported attribute

  on ..\..\..\modules\application_gateway\code2.tf line 101, in resource "azurerm_application_gateway" "application_gateway":
 101:       name                  = c.appg_http_settings.name_http_settings

This object does not have an attribute named "appg_http_settings".

This value does not have any attributes.