To install a Let’s Encrypt SSL certificate, log in to your ISPmanager control panel.
Go to the «WWW» or «WWW-domains» section.
Select the domain where you want to install the SSL certificate and click «Edit»
Check the box next to «Secure connection (SSL)».
In the «SSL certificate» dropdown menu, select «Let’s Encrypt certificate».
Click «OK».
On the next page, leave everything as it is and click «OK».
If your domain is hosted on your server and there are no access restrictions, the SSL certificate should be active within 10 minutes.