Getting 400 Bad Request when creating PostgreSQL flexibleservers/migration using azapi_resource

[cjdalan]

We're using azapi_resource to create a flexibleServers/migration. Using the code snippet below for creating it.

resource "azapi_resource" "migration" {
  type      = "Microsoft.DBforPostgreSQL/flexibleServers/migrations@2023-12-01-preview"
  name      = "migration"
  location  = var.location
  parent_id = var.targetServerResourceId

  body = jsonencode({
    properties = {
      dbsToMigrate                = var.dbNamesToMigrate
      migrationInstanceResourceId = var.migrationRuntimeServerResourceId
      migrationMode               = var.migrationMode
      migrationOption             = var.migrationOption
      overwriteDbsInTarget        = var.overwriteDbsInTarget
      sourceDbServerResourceId    = var.sourceServerResourceId
      sourceType                  = var.sourceType
      sslMode                     = var.sslMode

      secretParameters = {
        sourceServerUsername = var.sourceServerLoginName
        targetServerUsername = var.targetServerLoginName

        adminCredentials = {
          sourceServerPassword = var.sourceServerLoginPassword
          targetServerPassword = var.targetServerLoginPassword
        }
      }
    }
  })
}

Here is the error

Error: Failed to retrieve resource
  with x.x.x.migration,
  on .terraform/modules/x/x/main.tf line 201, in resource "azapi_resource" "migration":
 201: resource "azapi_resource" "migration" {
checking for presence of existing Resource: (ResourceId
"/subscriptions/x/resourceGroups/x/providers/Microsoft.DBforPostgreSQL/flexibleServers/x/migrations/migration"
/ Api Version "2023-12-01-preview"): GET
https://management.azure.com/subscriptions/x/resourceGroups/x/providers/Microsoft.DBforPostgreSQL/flexibleServers/x/migrations/migration
--------------------------------------------------------------------------------
RESPONSE 400: 400 Bad Request
ERROR CODE: InvalidInput
--------------------------------------------------------------------------------
{
  "error": {
    "code": "InvalidInput",
    "message": "Invalid input. Parameter name: 'MigrationResourceId'. Error: Invalid migration resource ID 'subscriptions/x/resourceGroups/x/providers/Microsoft.DBforPostgreSQL/flexibleServers/x/migrations/migration'.\r\nParameter name: MigrationResourceId"
  }
}