Manual Use of Certbot in Plesk Onyx?

Hello how can I manually call certbot? Ive had a look around and can't locate the letsencrypt/cerbot files? Attempting to simply enable SSL on mail.domain.com scripts. I have a proxy in the way for www, so don't want to have to script around the certbot on the proxy for www requests.

i.e.

find / -type f -name "certbot-auto"

shows nothing? Where can I find the application?

I also can't see the file or any familar directoris /live etc in amoungst these folders

find / -type f...

Manual Use of Certbot in Plesk Onyx?