I'm assuming that someone at the club would have to give ultimate approval, and "sign off" on the final design. Surely, some exec at Puma wouldn't have the final say?
I have seen people claim that Khaldoon himself signs the kits off. As far as I know, he commented in an end of season video that he liked the colin bell kit, and that's what led to that claim. I could be wrong.
But yeah, surely someone at the club agrees to Puma's designs.