If the license is installed correctly, you should be able to see it in the
About tag of the program dialog.
The license must be installed in the program folder. This is the folder where you also find the gui.exe file. The name of the license file must be license.xml. If your File Explorer is hiding file extensions, it may look like you have named it license.xml but still have an invisible file extension. Please right-click your license.xml file and check the file properties.
A more detailed description of how to install the license is available here:
You can also watch the video here: