I used to use a Mac computer.
The old “unidentified developer” error. Open up Preferences/Settings.
Go to Security and Privacy. Closer to the bottom of the screen, it will tell you something like “[app name] was blocked from opening because it is not from an identified developer” and next to it will be a button that says “Open Anyways.” Click on it, and you’re all good. You may need to put in an administrator password, however.