Nostr Connect is another term for NIP-46 remote signing. You might see "Connect with Nostr" buttons on apps, and this usually means NIP-46. The app wants to connect to your signer.

The flow is to scan a QR code or paste a bunker URL, approve the connection, and the app now uses your signer for signatures. Different implementations have quirks, with some using nostr+walletconnect:// URIs and some using bunker://. The underlying protocol is the same.

If something calls itself "Nostr Connect," it's probably NIP-46 compatible. Check the docs if you're unsure. With Signet, you should be able to connect.