Ah I see, good point. There are a few on amazon that are cheap as low as $6, but there is one that I like that is foldable for travel. Either way , the bent part where a phone would usually go could hold your stylus/pen when not in use. Win Win.
https://www.amazon.com/Nulaxy-Foldable-Compatible-Nintendo-Readers/dp/B07F8S18D5/
This is a metal one in the similar vein as to what /u/Michael-the-Great posted. I have one similar (the Power A Zelda one, not made anymore) and have liked it.