Well as someone who has played football and coached quarterbacks for a long time I will say there’s not one motion
Everybody’s different
From your classic over the top like Jim Kelly
To a three-quarter SideArm like Philip Rivers
Me personally as a lefty, I’ve always had a three-quarter SideArm delivery… Yet great spiral and touch
The biggest key is finding the correct grip for your hand size on the ball… What feels the best between the laces
Quick snappy motion …. The softer you toss the harder it is to throw a spiral… So if you put some juice behind it and Snap your wrist at the release it will greatly help
Not to mention all the foot work stuff that we could get into but that’s not important right now
Find the grip and release that feels good to you