This option is available if you enabled the Organize&Search feature package
1) Open the Desktop.com app
2) Open the link/URL in your web browser
3) Navigate to the installed plugins section in the top right corner of your browser and click the Desktop.com browser extension, then click Save link button
4) Select which workspace and desktop this link will be added to, change the title if required and click Save button on the top right.
How to import bookmarks from a browser to a desktop
How to import apps from a browser to the desktop
What are favorites and how do I manage them in Desktop.com?