It's a personal service, and for NIP-57 it has it's own keypair. I'm planning to make a separate secret for each app that needs to connect, but if I supply a new secret on the connect string, what's the use of the pubkey then?
It is better to create a unique private/pubkey for each NWC. Since you are putting the secret on the wallet connect String DO NOT use your personal key.
Current App wallet implemented it…! Pls look at our code..
https://github.com/starbackr-com/current/tree/main/features/walletconnect
Discussion
Pubkey is wallet pubkey. Client use this to encrypt content json which is the entire lightning invoice payment.