How do I install a security certificate for an alias (domain pointer) in DirectAdmin?

I have the following problem: I have 2 domains: domain1.example and domain2.example (domain pointer) => domain1.example.

Previously, I used Let’s Encrypt to create SSL for both in DirectAdmin and it was OK. But DST Root CA X3 Expiration error made my Let’s Encrypt alert and I bought paid SSL.

I bought ssl for domain1.example but domain2.example doesn’t have SSL.

How do I install SSL for the domain pointer? I’m using DirectAdmin version 1.61.5.