You need to sand both the inside and outside edges of the garage door.
How to repair a hole in a garage door.
Standing inside your garage use a piece of rough grit sandpaper to smooth the rough edges of the hole in the door.
Allow the filler to dry completely.
Spray each spring with garage door lubricant.
Sand and smooth the patch with a course grit sanding.
Use automotive body filler to fill the hole then sand smooth and paint to match.
Crumple up a small bit of newspaper or paper towels and push the wad lightly into the hollow area of the door surrounding the hole.
Slide a grocery bag or piece of cardboard behind the spring to protect the garage door.
Wipe off any excess then repeat the process on the other side.
Put a lag bolt with a round or flat head through the hole and a washer and nut on the inside.
You can then paint the head of the lag bolt to match the door and basically cover the hole.
Turn off the garage door opener if there is one so that the door will not move while you are patching the hole.
Apply a smooth layer of filler to the hole with the putty knife.
With the drawbar mounted and the holes drilled insert and tighten the attaching hardware that fastens the drawbar to the door.
Once the edges of the hole are completely smooth use a couple bursts of compressed air to remove the loose dust.
Mark the drawbar mounting screw holes on the garage door and drill the holes in the door.
The crumpled paper will serve as a lightweight block to contain.