SSL - explorer - ABAP - HTTPS

Please see attched  WORD file for problem description.

I got the certificates from SAP  (TEST)

I do NOT manage to access the URL without getting certificate error.

https://mydphdb0143.hpswlabs.adapps.hp.com:8400/sap/bc/ui5_ui5/ui2/ushell/shells/abap/FioriLaunchpad.html

Do I need to install something else?  On my PC  on the SAP SERVER?

What am I missing?

The Mobile expert is asking for P12 certificate

Thanks,

Moshe Yerushalmy