Go to Messaging and select the space.
Click Add +. If shortcuts were already added, click the last tab and select Add a website shortcut from the drop-down list.
Enter a name for the shortcut and the website address.
Webex | Add a Website Shortcut to a Space
By adding a website shortcut to a space, you can keep important information right where your team needs it. Space members click on a tab to open and browse any website from inside their Webex space.