Not able to extract single string from map stored in output

######### Variable in module ##############
variable "instanceTargetAttachment" {
  type = map(object({
    targetGroupArn = string
    instanceID = string 
    port = number
  }))
  default = {}
}

####### Actual Value passed ############
variable "instanceTargetAttachment" {
 default = {
    target-11 = {
      targetGroupArn = "arn:aws:elasticloadbalancing:us-east-1:730335241082:targetgroup/terraformTest-80/656f5c02aa6183b"
      instanceID = ["i-09b14edc562c8778t", "i-09b14edc562c8778t"]
      port = 80
    }
   
    }   
  }
}

I am not able to extract single value to target_group_arn in aws_lb_target_group_attachment

the value in the output is like

terraform output
WebserverInstanceId = {
  "webserver-1" = "i-00aa69a47495d5dcf"
  "webserver-2" = "i-0fa626c1a9ab4d52b"
}
targetGroupArn = {
  "terraformTest-80" = "arn:aws:elasticloadbalancing:us-east-1:730335241082:targetgroup/terraformTest-80/656f5c02aa6183"
  "terraformTest-81" = "arn:aws:elasticloadbalancing:us-east-1:730335241082:targetgroup/terraformTest-81/814f284b095c86"
} 

I want to use the values in a way that single target group is picked and attach all the given instances and then second target group and attach the given instances to that with the port given.

kindly help
Thanks