Loop back connection fault

I am facing this loop back connection issue. But I am using admin and password credentials for the project still it says bad user access denied. So, what credentials are required for this connection to be good.

It depends on the authentication profile you've configured the server to use.

In a default install it uses its own profile and the username/password is "opcuauser" / "password".

Thanks Kevin. As it was default install opcuauser was the credential. Since I have logged into the webserver with admin and password, there was no connection . So, I have changed the username to admin and now it is working. Thanks for the help.