Two unrelated domains on one server

[svennd]

I think you will need to talk to your hoster, since you have no access to a terminal. But multiple domains on one host is no problem. From Frequently Asked Questions (FAQ):

@josh

Can I get a certificate for multiple domain names?

Yes, the same certificate can apply to several different names using the Subject Alternative Name (SAN) mechanism. The Let's Encrypt client automatically requests certificates for multiple names when requested to do so. The resulting certificates will be accepted by browsers for any of the domain names listed in them.