Lemmy, although in a very well working state, isnt really deploy ready. The update procedure is a mess, the documentation is less than stellar and accessibility/onboarding for wannabe admins is rough to say the least.

You can find a compose file on github and you will need to make a config file for the instance with your domain and all on it.

A one click install sure is doable but most people who are able to do this quickly are very busy or wont do it for free.