The user should be able to create a shareable link.

• The administrator should be able to turn this feature off through the site's configuration
• The user should be able to get a shareable, private link to the exercise (not the regular view page). You can use URI fragment identifier as the key. All the logged-in users should be able to watch the exercise in this case.
• The user should also be able to select a specific user(s) to share the exercise with. In this case, they'll have access to the regular view page.