As soon as the basic installation of Joomla has been completed, the setup can be carried out. I had the following problem:  the installer always stopped halfway without warning. Ultimately, it was because of the PHP version. Only after I changed the server configuration to PHP7.2 did the installation work properly. After the installation I was able to switch PHP back to 7.4. The problem was caused by the Apache mod-evasive module. For one thing, there were many 403 errors in the operation of Joomla and new installations could not be set up. For this reason, I first switched off this module: