I’m trying to create a watch-only wallet for an nostr:npub1casacasahesdrpu6npfth2t0ae37a2cdwwg3c4fkt30v7gzffx3q7wtzdc wallet that uses a mobile key. How would I get the public key for mobile key (iPhone)? The article https://support.casa.io/knowledge/creating-a-watch-only-bitcoin-wallet-in-electrum doesn’t explain or is outdated.