I'm guessing you entered your Nostr public key into the Nostr address field and Snort said it was invalid. Which that would be. You need to enter in a Nostr address into that field that you own. It's like an email address. You can host your own or buy one from a provider. It's a bit technical... But some apps set them up for your automatically. Give https://primal.net a try for your next web app. But also look into more what Nostr can do beyond Twitter alternatives. Check out https://Nostrapps.com

Good review by the way.