How to solve "The source http://localhost:3000/ has not been authorized yet"

[MarcoBrian]

Hi I am integrating with RainbowKit the first time. I understand that it is required to set up a WalletConnect projectId, which I did so but I kept receiving this error "The source http://localhost:3000/ has not been authorized yet".

https://docs.reown.com/cloud/relay#allowlist => Even though in this doc it says localhost should always be allowed.