VEVOR Pet Door Replacement Flap, Compatible with VEVOR Flap Pet Doors, Measures 8.25" x 12.25" Longer Lasting, Weather-proof, Thickened PVC Dog Door Replacement Flap with Long Magnetic Strip (Medium)

I have a pet safe door. I ordered the Vevor replacement door the size will fit but it doesn’t have the same support at the top of the flap. The old one has like 8 ridges that slide into the top bracket of the door. How can I get the right one, or do you not have them?