I have a gas cap , that I think is the way it should be, but have no clue on the newer capless, sounds silly.
I have a gas generator and was wondering about sucking gas out of the truck for it, I have a couple suction pumps, with 3/8" plastic hose, But no way could I get the hoes down to the tank, there is something in there to stop that, I coil spring I think some one said.
The Honda CRV was the same , could not get a hose down to tank.
So I don't think a lock is needed, usually I think they just cut a hole in the plastic tank
Real easy with all the guys that lift their trucks.