Why can I not mention PURPOSE or Role in subnet creation "An argument named "purpose" is not expected here" in terraform

Question

I have a subnetwork module that I call from in my main.tf.

resource "google_compute_subnetwork" "vpc_sub_network" {

for_each = var.subnet_info
ip_cidr_range = each.value["subnet_ip_range"]
name = each.value["subnet_name"]
network = each.value["vpc_name"]
region = each.value["region"]
purpose = "INTERNAL_HTTPS_LOAD_BALANCER" --> unable to mention
role = "ACTIVE" --> unable to mention
}

I have checked in the documentations of terraform that we can mention Purpose and role when we create a subnetwork

in my main.tf

Provider "google"{
creds.....
}
module "vpc_sub_network" {
source = "./modular_approach/modules/general_network/"
}

Error

 on modular_approach\modules\general_network\main.tf line 5, in resource "google_compute_subnetwork" 
 "vpc_sub_network":
        5:   role = "ACTIVE"

 An argument named "role" is not expected here.