Gas cap question

[dave`12]

Just got the wife a 2018 Colorado v6. Instead of a gas cap (like any 1/2 way intelligent designer would include) this thing has basically a hole with a spring cover. So anybody can siphon gas or put something into the tank.

Not sure what GM was thinking (are we really that lazy?) but I would like to put a locking cap on this. It's not threaded in any way.

I looked around and found some for 2015 silverados, but nothing that actually says it will fit my truck.

So does anyone know if there is something that will work?

thanx