Apple MFi - Homekit Software Authentication (401)

Hi,

We were trying to setup communication with the apple MFi server, according to "Software Token Authentication Server Specification R2. pdf ", we completed the certificate request, and then did the following things in order(Tested http request with Postman):

1. downloaded .pem file from MFi Dashboard

2. In Postman settings, added the .pem file as CA certificate and added .pfx file (which is an non-EV SSL certificate we alyeady have) as client certificate.

3. correctly entered the request URL , header and body and then pressed the "send” button

4. got the error returned by Apple Server: "<title>401 Authorization Required <title>"

we have tried many times, but always got this error, our status of Product Plan now is "testing" .
Can our Licensee server use an ordinary SSL certificate（instead of DigiCert EV SSL certificate）during testing period? And what caused the above error ?thanks in advance.