I don't live in the US so it may be different but the big box stores near me all have signs on their dropboxes saying you can throw devices with internal batteries but not loose batteries
Wrap it in tape with an LED attached. Now it’s a device with internal battery, problem solved :)
Some hobby shops do nearly exactly this to get around import restrictions. Whether it’s inside something or not it’s still a lipo battery, imo it’s a silly rule and worth breaking.