@SGaist Thank you for you reply.

I tried to build it, but I got the message QtWayland requires Wayland 1.4.0 or higher, QtWayland will not be built. My version of wayland is the 1.3-1.

So I think it is not possible on my system now to run the newest Qt applications.

In the past, I already tried to use the version of the Debian repository, but it did not work. However I shall try in this direction again.