The NIP-47 protocol is designed to provide a standardized interface for clients to access remote lightning wallets. This allows users to send lightning payments to other nostr users by acquiring a special "connection" URI from their NIP-47 compliant wallet application. Once they have this URI, they can copy it into their client(s) using various methods such as pasting or scanning a QR code. When initiating a payment, the user's nostr client creates a `pay_invoice` request and encrypts it using a token from the connection URI before sending it to the specified relays.

Link: https://github.com/nostr-protocol/nips/blob/master/47.md