Rest API Smartcard Auth

Hi

I have seen there are a couple of threads around smartcard auth. None of them help with my issue \ lack of understanding. Basically here is what I am trying to do. I am trying to make a REST API call against VMware’s VRA. The VRA Authentication process is to return a token once I authenticate. I am able to authenticate with an account that DOES NOT require smart card auth. When I try to use an account that DOES require a smart card I fail. So when I do this via the browser, creds seems to be passed through and then I am prompted to select my cert.

I have tried using both Invoke-Webrequest and Invoke-Restmethod with and without the certificate parameter. The API call has the following payload
{
username = Username
password = Password
tenant = Tenant
}

Thanks