Did you read the documentation? Is just one big button on the main page. https://docs.cashu.space/

Cashu is a e-cash mint on LN. Cashu work like a secret token, minted from your sats from a LN channel. You can send them exactly like a LN invoice. Once you receive them are redeemed the sats.

Call it like a secret envelope in which you put some sats and hand them over to somebody else. That somebody will open the envelope and take the sats and put them into his own LN channels. Done.

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