Got to https://<website>/.well-known/nostr.json

That should give you a list. The Npub will be in hex so you'll have to bech32 encode it to be Npub.

https://bitcoinveterans.org/.well-known/nostr.json
https://shenandoahbitcoin.club/.well-known/nostr.json
https://virginiafreedom.tech/.well-known/nostr.json