sudo mkdir /usr/share/adminer
sudo wget "https://www.adminer.org/latest.php" -O /usr/share/adminer/latest.php
sudo ln -s /usr/share/adminer/latest.php /usr/share/adminer/adminer.php

echo "Alias /adminer.php /usr/share/adminer/adminer.php" | sudo tee /etc/apache2/conf-available/adminer.conf
sudo a2enconf adminer.conf
sudo systemctl reload apache2

Adminer aufrufen mit:

https://mywebsite.de/adminer.php