Any camper supply store will hae what you need.
Campers World is one that comes to mind, Although I personally will never shop there for reasons I will not get into....
You may or, in the case of the one in Center Conway NH, May Not get one.
They look nice but it's best to strap them around the middle with a luggage belt when traveling. I've lost 2 on the road. Now I just take it off for travel.
I got mine at a mom and pop propane place where they repaired propane things as well as sold propane. It only cost a few dollars more than Amazon! Also found real Butyl tape, something I had asked all over town for and couldn't find!