Could not find the Qt platform plugin "xcb" on Redhat virtual machin

Question

I downloaded and installed QT5.15.12 from the official website using the command:

$ wget https://download.qt.io/official_releases/qt/5.15/5.15.12/single/qt-everywhere-opensource-src-5.15.12.tar.xz

I used the following command to configure the project:

$ ./configure -opensource -confirm-license -release -prefix /usr/local/Qt-5.15.12

Then, I used gmake and gmake install to compile and install Qt on my system. I am running Red Hat 9.3, and I did not encounter any issues during the compilation and installation.

To test my installation, I compiled the project located at ../examples/demos/clocks in the Qt directory. When I run the executable, I encounter the following error message:

Warning: Ignoring XDG_SESSION_TYPE=wayland on Gnome. Use QT_QPA_PLATFORM=wayland to run on Wayland anyway.

qt.qpa.plugin: Could not find the Qt platform plugin "xcb" in ""

This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.

Available platform plugins are: eglfs, linuxfb, minimal, minimalegl, offscreen, vnc, webgl.

[2] 1245457 IOT instruction (core dumped) ./main

I tried to set the QT_QPA_PLATFORM environment variable to "offscreen," but I received the following error message:

Warning: Ignoring XDG_SESSION_TYPE=wayland on Gnome. Use QT_QPA_PLATFORM=wayland to run on Wayland anyway.

This plugin does not support propagateSizeHints()

This plugin does not support propagateSizeHints()