Anyone can invite other users to In Reach by clicking on the invite icon on the icon on the action bar of the content.
The invitee receives an email invitation . Clicking on the Go to content button within the email would redirect him to the playbook to view.
However , if he does not have access to In Reach , then on clicking the Go To Content button in the email , he will see the access denied message .
The related notifications are also seen on the notification
Once the In Reach Admin activates this user , the invitee can access this content.