Can anyone help me understand how to set up DNS specifically in hover.com?

I have added a CNAME for:
Host: www

Target: xxxxxx.up.railway.app

But this does not seem to be working even after having giving a few days to propagate. I have read documentation on how to setup up public networking with other domain providers, but they do not seem to align with the UI in hover and I am not familiar with DNS enough to know what I could be doing wrong.

I tried Host: @, but that is not allowed in hover.

I tried Host: * , but that causes an error "CNAME can not co-exist with other data". There is already an A record with * and an IP that was put there by hover.

Thanks.