"npub.cash uses Cashu-Address, a protocol built on Cashu and nostr. Cashu-Address allows a web server to provide Lightning addresses and mint ecash form the user's preferred Cashu mint. The user then redeems the ecash when they come back online."

its on the webpage

dont got time for nostr now, work calls. Enjoy the rabbit hole, tag me if you got more questions after your tried it out stu

Yes. It's a lightning facing eCash wallet, so you can receive to it via lightning, and your sats are stored as eCash.

You can then withdraw to an eCash wallet (like Cashu.me) and from there send sats via the lightning network.