Touchscreen Monitor and DietPi?

have attached a normal Monitor with Touchscreen abilities to my Raspberry/Dietpi via HDMI. The Monitor shows the LXDE desktop. Very good. But how to I get running the touchscreen abilities? I plugged in the USB connection Monitor/Raspberry but it does not work. Guess I have to install any kind of packages?
What is to do?
Kind regards.

I think it depends on the model. What’s the exact model of the monitor?

This is the one:

HANNspree HT161CGB

did you tried plain Raspberry OS if it is working there?

No, might it not work with linux at all?

Honestly I don’t know. I guess there is nobody in this forum who tested it with this device. But if you have a spare SD card, you could give it a try and test it using plain RPi OS.

OK, I will try it during this weekend. Thanks

I have tested it. It did not work either.

But then I connected the USB Raspberry Port to USB-C Monitor Port with an extra adapter (USB+Power to USB-C) and now it works fine.

Thank you all

Probably there was not enough power for the touch screen to be working?

Yes, it was a power problem. Solved it with an Y cable.