AirClip

This airtag case is designed to attach to any flat surfaces items like clothing, book, backpack ,etc.
There is a hole to mount this clip with a screw on flight cases or other items.
Not like airtag keychain or loop, this clip-on airtag holder can be easily attached to clothings, book, backpack and mores scenarios, no dangling.
 

I printed it with PETG and a .6mm nozzle and .15mm layer height to help w/ smooth profiles, but you can probably get away with larger layers to print faster.
You need a brim to print this easy standing on its side without support.