If you by some slim chance also have one of these, then I hope I may be of saving grace if you too have a missing handle for this device.
Hole depth is 10mm. I used M3x16mm screws cut down with a washer to have 8mm inside the handle.
I sliced a .16mm and 100% infill and used supports under the flat area. Print oriented with both ends on the bed.
The author marked this model as their own original creation.