This mutation is used to create a new staff member for a tenant using an already existing userID. Return information can include permissions, staff member details, and organizational unit details. **Returns:** Returns the newly updated staff member data.
userId: UUID
The user ID of the existing user who will be used to create a new staff member.
username: String
The username for the new staff member.
tenantId: UUID
The tenant that the new staff member will be associated to.
organizationalUnitIds: [UUID]
