The support ticket is an option when you click on the support button top right
You're clicking on the wrong button, you don't want to activate the full version (that'll need a purchased key) but to continue to the trial.
However, it looks as if the graphic driver of your emulator is out of date, that will also cause problems later - please update it.
Alternatively, you'll have to wait for the Mac standalone trial/version, currently only the steam version of RMMV runs natively on Mac.