I follow the instruction in https://developer.yahoo.com/oauth2/guide/openidconnect/gettingstarted.html for the sample URL request, but I keep getting error "Developers: Please specify a valid request and submit again." I expect I got the yahoo login page to login as yahoo account. any ideas?

Sample URL¶
https://api.login.yahoo.com/oauth2/requestauth?clientid=dj0yJmk9WGx0QlE0UWdCa0hKJmQ9WVdrOWNrNUhXVnBhTkhFbWNHbzlNQS0tJnM9Y29uc3VtZXJzZWNyZXQmeD01OA--&responsetype=code&redirecturi=https://yahoo.com&scope=openid%20mail-r&nonce=YihsFwGKgt3KJUh6tPs2