If you want to run the QSS-M app (because it was not downloaded from the App Store), you'll need to make it executable and remove any restrictions:
If you drag QSS-M.app (or the folder with it) to the terminal window it will show the path.
cd path/to/QSS-M.app
Get the path from dragging to window or just type it if you know it.
sudo chmod +x QSS-M.app
This command gives the app permission to run.
sudo xattr -r -d com.apple.quarantine QSS-M.app
This removes any restrictions that might prevent the app from opening because it was downloaded from the internet.