I am trying to deploy the website with backend and frontend on the same deployment but the domain of every deployment does not match my registered domain that is in settings. It is not a custom domain but the .vercel.app one. I want each deployment to have that domain as I need that for my backend and frontend connection. I also have tried promoting to production to assigned the desire domain but it does not update or add the domain. I have been deploying as production but that still does not fix it. This is causing issues with my google login because with my backend configuration I need a backend url to redirect when trying to login with authO.
The domain troubleshooting guide can help with most custom domain configuration issues. You might be able to use that guide to solve it before a human is available to help you. Then you can come back here and share the answer for bonus points.
You can also use v0 to narrow down the possibilities.