How to fix "Vault location [kv/my-client-service] not resolvable: Not found" when I am trying to connect HashiCorp Vault using AWS IAM role?

I fixed this issue after updating my vault policy with the below configuration:

path "kv/*"
{
  capabilities = [ "read", "list"]
}

I was able to start my application with the vault properties getting fetched.

I think the policy update in your case is apt:

path "kv/*"
{
  capabilities = [ "read", "list"]
}

Direct it to the correct path of your secrets will resolve your issue.