I believe I saw not long ago someone asking about a Clip or screw on tailgate. Not sure which one it was tho. I'm trying to find it now hopefully to help.
I had one of those little black plastic rivets pop out recently. The parts department counter Guy at my local Ford dealership just walked back to one of his parts bins and gave me three of those rivets, free of charge.
“Use one and put the other two in your glove box,” he said.