Could someone explain to me step by step how to do it when I have Ubuntu 22.04 with a database and phpmyadmin. What do I need to do first to start the installation

You have everything explained on their website step by step.

Ye, but I moved the folder on my vps to the http folder so I could access the install file through the browser and after configuration the bot didn’t want to connect so I’m probably doing something wrong

You have a log where you can see the errors.

Do I have to install these PHP extensions separately or are they installed with the PHP installation?

You have to set the appropriate PHP version in the installation.