Paste an existing client config, then generate a new client profile with the next IP address, a fresh key pair, a QR code, and the matching peer block for the server.
Only the address and the new device key pair are editable. Everything else is carried over from the pasted config.
The Generate button uses the browser's built-in Web Crypto X25519 support. You can still paste keys manually.
Import this on the new device with the WireGuard app.