Cannot create AWS Api gateway with mTLS

Is it possible to create an AWS “custom domain” with mutual TLS using terraform ? couldn’t find any examples.

My code:
resource “aws_api_gateway_domain_name” “example_domain_name” {
domain_name = “my-domain”
regional_certificate_arn = “my-certificate-arn”

endpoint_configuration {
types = [“REGIONAL”]

mutual_tls_authentication = {
truststore_uri = “s3://my-bucket/truststore.pem”

I get this error:

│ Error: Unsupported argument

│ on line 98, in resource “aws_api_gateway_domain_name” “example_domain_name”:
│ 98: mutual_tls_authentication = {

│ An argument named “mutual_tls_authentication” is not expected here. Did you mean to define a block of type
│ “mutual_tls_authentication”?

I was able to successfully create a custom domain without mtls so i think all the other parameters are fine. Doesn’t seem to work with mutual tls