N.B. There si an ongoing issue with Digicert, the certificate provider, leading to certificates staying pending.
For now, you need to follow the procedure using either Safari, Edge, or firefox-esr (very easy to download and start).
Quick documentation
If you already requested certificates on one way or another, and/or you are a confident person, just:
1. Go to http://www.digicert.com/sso;
2. Choose your institution, and login;
3. Request a Grid Premium certificate;
4. You can now export the certificate from your browser if needed.