Patterning is your best friend. One can determine where the gun is shooting vs where you are looking and rectify.
That is good advice. I am fortunate enough to live reasonably close to Orvis' Sandanonna facility in NY. As a retirement treat some years ago, my Mary arranged some instruction for me there. Included was a session at the patterning board with two men who knew what they were doing and a Try Gun.
I don't know how to adjust the Try Gun but the process from my end was simple and very graphic. You can do that part yourself.
They had a steel plate, painted white with a black spot in the middle, placed 16 yards from a shooting point. They handed me the Try Gun and told me to look at the spot and then to mount the gun and - without looking at the bead - point the gun at the spot and shoot. They repainted the plate and the spot after each shot and adjusted the Try Gun. By the time they were done, each shot that I took was centered on the black spot.
You could do some of this with a piece of cardboard, a couple of spray cans of paint, and your shotgun. At least you'd know if it's shooting where you look.