ServiceDesk plus - URL is not found in widgets

ServiceDesk plus - URL is not found in widgets

when i go to Self service portal customization to create a new widget and add a new url, let's say " www.google.com" it says url not found or url is wrong. when i add http or https for ex: " https://www.google.com". the page doesn't even load.
What is the issue?

                  New to ADSelfService Plus?