First you need to make sure the role that you created for that workspace has the View Item permissions added. Next ensure that that Role is associated with a group that includes the users that need access to the workspace. Check the Main Menu Designer in the Administration/Setup/General tab to ensure the workspace is listed organizationally where you want it to be viewed in the Main Menu. And lastly you will need to log out of your tenant and then back in to view the Workspace in the Main Menu as the Main Menu is cached.
John Hill Support Specialist Product Support Autodesk, Inc.