Cognito google login error on redirect. "username attribute mapping required"

Trying to setup a cognito user pool with google sign in. When testing with hosted UI. The google sign in page appears and lets you sign in using google. The redirect happens the url on the browser shows "https://www.example.com/?error_description=username+attribute+mapping+required&error=invalid_request#"

I have already mapped user name and email to google sub and email respectively

Please can you someone with knowledge on this help me solve this