Hey @myialine! When you sign in does it also say The provided redirect_uri is not in the list of allowed callback URLs next to the “Callback URL mismatch” message?
If so, you can look at the URL on that error page and find redirect_uri. That will be the URL that Auth0 is expecting in “Allowed callback URLs”
E.g. If it says “https://yourdomain.auth0.com/authorize?client_id=yourclientid&**redirect_uri=http%3A%2F%2Flocalhost%3A8080**…”, that means you should use http://localhost:8080.
If that doesn’t help, can you click on “Logs > Search” in the dashboard and tell me what the “Description” message says for the failed login? Thanks! 