basically you gotta do what it says at first which is drag the app to your app thing and stuff, then you gotta go to settings, privacy thing or something, then click the lock, then you gotta enter ur password of ur pc and then u can change it so the app is allowed to work. I hope it’s simple enough, cuz I dunno how else to describe that.
you might not have the lock at all if you're on a newer update of MacOS. You can usually get around the popup by right click opening however.
If that doesn't work then you're looking for something like "clangen was blocked from use because it's not from an identified developer" with a button for "open anyways"