If your device is turned off? 😅

And also if your device is on but your LN wallet is not open it may doesn't work to wake up the app with push notifactions to send something.

Bolt12 will adress this too, but that can take another while in the speed things get pushed in this space 😆

I also printed tokens on sealed bills, so I can just give it to people I meet. Of course in this moment they need to trust me until they are online, scan the QR and verify thet it actually is one token worth 4'096 sats (tokens are always some potency of 2)