You can run multiple php versions on Ubuntu without any issues. But you require multiple PHP versions if applications are built in different PHP versions like php 7.1 and php 7.2.  Here, we will installPHP7.4, and PHP8.1 on the server.

To Renew Let’s Encrypt certificates in nginx

How to Remove a Domain from Certbot and NGINX

Command history allows you to find and reissue previously typed commands