How to Manually Change SSL Certificate?

I end up getting a self-signed certificate every time I try to assign an SSL from Manage SSL, Hostname SSL, or MailServer SSL on Cyberpanel. I have a properly working certificate generated through nginx/certbot. I’m thinking of just manually changing the certificate used for cyberpanel with that from certbot. Where can I find the files associated with the certificate and key for Cyberpanel’s Hostname SSL and MailServer SSL?