There are several different license types in ManagerPlus.  User licenses is how ManagerPlus is sold and scales with organizations.  Licenses grant access to ManagerPlus and can control the access level each user has.  Below is an explanation of the different license types.

Key Benefits and Features
License NameAccess Level
Named UserFull Access to ManagerPlus and sub applications - Controlled by security roles
Mobile UserLimited to mobile access only with limited security role control
OperatorAccess to the Operator Companion
RequesterAccess to request portals
Use this Feature To...

The different user types are designed to help guide different users in the roles.  Talk to your customer success manager to determine if you are configured correctly in your different user types.

You can also check out this article on creating new users.  

Work Orders can only be assigned to the "Full User" and "Mobile User" license types.

When creating new users you select which user type you want to create.  Below you will see a screenshot of first step of new user creation: