Setup VNet integration for an Azure App Service (web app) via Terraform

I am trying to setup VNet integration for an Azure App Service (web app) via terraform, and the below is the code I have been using:

resource "azurerm_subnet" "network_app_wtier_subnet" {
  name                 = "App-Web-tier"
  resource_group_name  = azurerm_resource_group.network_rg.name
  virtual_network_name = local.vnet_name
  address_prefixes     = ["10.1.1.0/27"]

  delegation {
    name = "delegation"

    service_delegation {
        actions = [
            "Microsoft.Network/virtualNetworks/subnets/action",
            "Microsoft.Network/virtualNetworks/subnets/join/action"
          ]
        name    = "Microsoft.Web/serverfarms"
      }
  }
}

... and I am getting the following error:

> Error: expected delegation.0.service_delegation.0.name to be one of 
> [Microsoft.ApiManagement/service 
> Microsoft.AzureCosmosDB/clusters
> Microsoft.BareMetal/AzureVMware Microsoft.BareMetal/CrayServers
> Microsoft.Batch/batchAccounts
> Microsoft.ContainerInstance/containerGroups
> Microsoft.Databricks/workspaces Microsoft.DBforMySQL/flexibleServers
> Microsoft.DBforMySQL/serversv2
> Microsoft.DBforPostgreSQL/flexibleServers
> Microsoft.DBforPostgreSQL/serversv2
> Microsoft.DBforPostgreSQL/singleServers
> Microsoft.HardwareSecurityModules/dedicatedHSMs
> Microsoft.Kusto/clusters
> Microsoft.Logic/integrationServiceEnvironments
> Microsoft.MachineLearningServices/workspaces Microsoft.Netapp/volumes
> Microsoft.Network/managedResolvers
> Microsoft.PowerPlatform/vnetaccesslinks
> Microsoft.ServiceFabricMesh/networks Microsoft.Sql/managedInstances
> Microsoft.Sql/servers Microsoft.StreamAnalytics/streamingJobs
> Microsoft.Synapse/workspaces Microsoft.Web/hostingEnvironments
> Microsoft.Web/serverFarms], got Microsoft.Web/serverfarms
>     │
>     │   with module.paired_regions_network.azurerm_subnet.network_app_wtier_subnet,
>     │   on modules/network/main.tf line 49, in resource "azurerm_subnet" "network_app_wtier_subnet":
>     │   49:         name    = "Microsoft.Web/serverfarms"

The error itself is contradictive : so, it expects Microsoft.Web/serverFarms, gets Microsoft.Web/serverFarms, but still errors?

Any idea how can I fix this?

EDIT

The configuration I was using when I initially wrote the post is the following:

terraform {
  backend "azurerm" { }

  required_version = ">= 0.14"
  required_providers {
    azurerm = {
      source  = "hashicorp/azurerm"
      version = ">=2.50.0"
    }
  }
}

Which should accommodate for any updates, I guess. Right?

Updating it to more recent versions (below) resulted in the same error.

terraform {
  backend "azurerm" { }

  required_version = ">= 0.15"
  required_providers {
    azurerm = {
      source  = "hashicorp/azurerm"
      version = ">=2.72.0"
    }
  }
}