Thank you!
To disable phpMyAdmin I used this command:
sudo a2disconf phpmyadmin.conf
sudo /etc/init.d/apache2 restart
To reactivate, I used this command:
sudo a2enconf phpmyadmin.conf
sudo /etc/init.d/apache2 restart
As I changed the server, it no longer worked. Only later did I see that the construction of the archives was different.
To deactivate and activate, is there a command also the same as above?
Or just through this? -> You can 1. change URL, 2. strict IP or 3. password required.