Any plastic coin case should work fine. I've made dozens and the Switch has no problem reading them, though they seem to read a bit faster with a Pro Controller rather than the Joy-Cons. These are the ones that I bought and they work fine:

https://www.amazon.com/gp/product/B088DCYT4D/ref=ppx\_yo\_dt\_b\_search\_asin\_title?ie=UTF8&psc=1