What is needed to request a server through authorization with a certificate?

Question

Digital certificates

Is it possible to connect to the server with only a .cert extension certificate file and a .key file. They were sent by the company on which the server is located.

Answer 1

Ask them!
How do we know?

Answer 2

Can. If the certificate is issued by the company itself, then ask them for their root certificate - otherwise the browser will start yelling about untrusted certificates. And better - ask to send a certificate in .p12 format - you can immediately install it into the system and select it when the server requests a certificate. Otherwise, you will first have to collapse these three files yourself - the certificate, key and root into .p12, because you can’t just put the certificate into the system.
After installation, simply select a certificate from the list (and if the browser automatically gives it away, you don’t need to do this either)