Ugh, I don't understand this one yet. So many rabbit holes to undertake.
Is this e-cash? And chaumian mints or cash?
Discussion
"Cashu is a free and open-source Chaumian ecash system built for Bitcoin" taken from https://cashu.space
It's like a bank check for Lightning. It's just text so the person can be offline and just scans a QRCode. It can check the value and mint offline. So when it gets online again it just has to redeem the sats in the "bank" the mint.