DK 8.3.0 and MariaDB: Driver not found

[Christoph]

Hi,

I'm just configuring a fresh DK 8.3.0 Flatpak on my also fresh installed 
Kubuntu 24.04. I'm using a mariaDB on a NAS for storing all things, and with 
my home pc it works fine, also with DK 8.3.0, also with Mint or Kubuntu.

But my fresh system on my notebook a database-test returns me an error 

"Der Test der Datenbankverbindung war nicht erfolgreich.
Die Fehlermeldung lautet: Driver not loaded Driver not loaded"

This error also appears with DK as appimage. What is missingß How can I fix 
this problem?

Greetz
Christoph