Integrate with Xero - can't connect

I’m building an app for my company and tried to make it integrate with Xero.
I have put in all the environmental variables as well as set up in the developer portal. But whenever I click Connect to Xero from my admin dashboard, this shows up:

This is the link of the app and you can go in to try
I’m not sure what i’m missing here. Any help will be great

Hey, Sarah! Welcome to the Vercel Community :waving_hand:

I actually get redirected to Xero log in page :eyes:

CleanShot 2025-04-29 at 11.20.09

I just added that in, but even I’ve signed in it’s still not connecting.
I’ve just restored to the previous version.

I don’t have a Xero account to verify. However judging from the error, it seems you can’t authenticate. I’d check your environmental variables and credentials are correct.