If you're specifically looking for version 8.2.0 of MKVmerge GUI and it's not available through the main download channels anymore (as versions are regularly updated), you might need to:
: A new feature added support for displaying queue progress directly on the taskbar button. Mkvmerge Gui V8-2-0 Download
If you are new to this version, here is a 30-second starter: If you're specifically looking for version 8
