Mac download of the new Launcher for PlatinumQuest 2.10.0+ 
Supported: Mac OS 11 and above 

Please note that you will have to bypass Gatekeeper: Settings > Search > Gatekeeper > Allow this application.

If it still doesn't work, open a Terminal window in the same folder as the app, then run: xattr -d com.apple.quarantine PQLauncher.app