Firebase: Connect custom domain for Firebase Hosting

I was getting the message "Unexpected TXT records found. Continuing to watch for changes." as Firebase tries to verify my domain ownership.

Depends on your domain registrar, you may need to set the TXT records with host "@" instead of the actual host name as provided in the instruction. It solved the issue with my registrar (namecheap).

Ref:
firebase - Adding custom hosting domain: "Unexpected TXT records found. Continuing to watch for changes." - Stack Overflow