• Right click > add new user 
• Extension dropdown > Open Full List > Users > Invite users (top right corner) 
• Type in your coworkers email that they are using and click invite. 
• The user you have sent your invitation request to (if on the same app ‘full list page’ ) gets a notification under requests. 

To work with each other you need to make sure you have added each other through the app > then confirm the request