Please be aware that following changes to macOS by Apple a few releases ago, if you make a Mac game having unticked the option to build for the AppStore, and you then share the zip file GMS2 makes for you with others via the internet, they will not be able to open the application and will receive a warning message that the file is damaged and should be moved to the trash - as shown on the following apple support page: File quarantine and malware detection.
This is because the act of downloading a .zip file containing a .app will be treated by the Quarantine service on the Mac as a potential security threat. This restriction does not affect non-AppStore apps shared using a USB drive or stored on a local network drive - only when downloaded from the internet.
Currently, the only way for the user to then play the game is to remove the application from quarantine using the commands given below, entered into a Terminal window.
Please be aware that the same "damaged" message is shown if you have accidentally sent out an AppStore-enabled package. In this case, your player may be asked to log into to their AppStore account first and then be shown the damaged message.
Open a Terminal window and type the following command xattr -d com.apple.quarantine and then leave a space, and then drag the .app file onto the Terminal window and "drop" it, so Terminal will append the full path to the file for you:
And then press Enter/Return to actually run the command. Note that you don't get any "success feedback:
Now run the app. It should no longer be quarantined.
This guide replaces the advice in https://help.yoyogames.com/hc/en-us/articles/216753168