Its a variation of a screwball.
In basics, you throw a fastball, and in the moment before release, you turn your arm over so that the palm of your hand is facing outwards.
There have been a few lengthy threads about this. I would suggest a search. It’s actually a variation of a slider/cutter, not a screwball.
its a variation of a changeup with screwball like spin
Actually, the gyro is said to not move, because of the bullet like spin it should be the same as the fastball. There have been pitchers who would try and throw sliders,screws,sinkers, etc. and they would get the gyro spin. The spin looked like it made the pitchers pitch more effective, I believe i saw a clip of a Japanese pitcher who threw a sinker, like a gyro, and it had a great break.