two more into the drywall. I can't remember if I got special screws for the drywall only area, but I think I did.
My frame is one that can slide and rotate. The center line of the frame is far left of the center of the TV. The right side screws went into the stud. And then I slid the frame/TV connector to the far right of the frame to center everything.
I've got a 65" Samsung QLED. And it's holding great. I was paranoid for a couple of weeks, but it's been holding for a year now just fine.
Best of luck.