Hey @Fisher71. Since the provided screws are too short, your best bet would be to go into your local hardware store like Lowe's or Home Depot to have them give you a good recommendation. I would bring the screws we have included with you, and maybe even the mounting bracket, that way this gives the workers a good visual of what you are needing. From there they can recommend you longer screws with hopefully the same screw head type and style so you can install this in your garage. Feel free to include pictures of what kind of screw you end up using in case other neighbors in the Community run into a similar concern down the road, and know exactly what to look for. Hope this helps!
I had to use a combination of screws. The distance between the screw holes in the mounting bracket is 1.5 inches or larger. I could not position the bracket so that all four holes would hit a 2x4 wall stud behind the drywall. I used 2 of the provided screws with the provided wall anchors and 2 longer wood screws to screw into a 2x4 wall stud. The combination worked fine.