The case has a small area to slide a metal lanyard through if you wanted to do that. 6-12 inch I think 1/8 metal lanyard is about .50 at the big orange store. The loop clip for it is another $1-2. The magnets are available at a craft store.
https://www.amazon.com/GPS-Tracker-Optimus-Bundle-Magnet/dp/B01KKVKQ66

