Did I break my Gas Filler Neck Flap/Cover? Or is there one on a 2010?

I did find this thread, but didn't really make me feel better.

Today before filling up, I put a bottle of Red Line SI-1 Fuel Cleaner in my 2010 Base Crewmax, and had some trouble getting the damn thing out, as the bottle has it's own ribbed neck. Mine has a stock gas tank.

After untwisting the bottle out of the filler neck, I noticed there was no "flap" or hinged little cover like there is on many of my other cars. Thought maybe I knocked it off and it went down the abyss

Is there supposed to be such a thing? Here is the best photo I could get:

 

You never had one. You're fine.

 

Thanks for the confirmation!