Add users that would be using the PPR and/or Legendary. At a minimum, you should add one users with all security privileges.
Security Privileges
Allow PPR Configuration - This user would have permissions to change the PPR unit's parameters and configuration. Typical user roles are supervisor and maintenance.
Grant Legendary Access - This user will have the ability to securely login to Legendary and review/approve records in the cloud rather than on the PPR unit. Typical users roles are supervisors and quality team.
Legendary Admin - This user will have the ability to manage user list in PPR and Legendary.