I just saw that The Perfect Server uses the original Let's Encrypt and not the package from the Debian distribution. Will ISPConfig also work with the package from Debian?
Which version of the Perfect Server Guide and which version of Debian? Let's Encrypt changes their client often, so it is possible the latest Let's Encrypt client is needed. Besides, if the Perfect Server Guide installs something not from the usual OS repository, I would assume it is because the package from OS repo does not work with ISPConfig setup.
Debian 10 with the corresponding The Perfect Server using Apache. Let me rephrase: besides of the version (which can be used from bullseye with appropriate pinning) are there incompatibilities with the Debian package and ISPConfig?
No, but in the past, the Debian certbot package stopped working and became incompatible with LE as Debian does not ship new versions within a release and it's likely to happen again on Debian 10, that's why we choose to not use the Debian package.
