Cat Door Cover

we have a Cat door cut into the Garage door and we lost the... Door? For it. it's like a cover to lock the cat in the garage when she is a pest. simple design for a standard 6.15 inch by 8.85 in (156mm X 225mm) Slot. print at 100% infill  I added the crossbars so that the cat couldn't bend it out of the slot.