OCI Error Message: AvailabilityDomain could not be inferred from the Request

When I try to create an instance on OCI with the following Terraform code (it continues after the last line), I get the following error.

AvailabilityDomain could not be inferred from the Request

I think I have the right availability domain and I cannot figure out why I am getting the error.

resource oci_core_instance "tokyo-proxy" {
    compartment_id      = var.tenancy_ocid
    display_name        = "tokyo-proxy"
    availability_domain = "Gumm:AP-TOKYO-1-AD-1"
    ...

I wonder if someone can help me out.

I fix this by executing the oci CLI command: oci iam availability-domain list
I found that the ad name was wrong.