No User Authentication Possible/ Certifcate Troubles

[tessmills]

I feel like the biggest idiot, but I can't find a solution for this:

I have received a .ovpn and and *.crt file from an organisation in order to log into their server.

The ovpn-file contains the following lines:

pull
ca *.crt

I have the ovpn-file and the certifcate in the same folder on my device.

I can drag the ovpn-file inot OpenVPN Connect and it creates a profile. However, when I want to assign a certifcate, it says "no external certifcates imported". If I try to import a certificate (Certifcates & Tokens, Add Certficate) OpenVPN does not accept the certifcate I have - it acts if it's the wrong format.

Do I need to change something about this certificate? Do I need to create an additional certificate for my device? If anyone has any ideas, I'd be very grateful.