In the Safari browser, go to the webpage 127.0.0.1:631/printers.
Note: If you get an error message such as "cannot connect" or "web interface is disabled", start the Terminal app (in Applications > Utilities) and enter the command: cupsctl WebInterface=Yes
Troubleshooting:
If user name and password is not working to save the default settings. Make sure to remove any spaces on username.