How to add Resources / Users to a Project

Users are typically added from Resources > Planning.

From the Workload tab	Find the name of a user click on + Allocate and select the Project.
From the Scheduling tab	Find the name of a user click on + Allocate and select the Project.
From the Access to Project tab	Find the name of a user click on + New and select the Project.
From the Team tab	Only for External Users with a profile based on Standard Access External. Click + Add, then Existing External User Select a user from the drop down list and click OK.
From the Project Users tab	Only for External Users with a profile based on Stakeholder / Restricted Access. Click + New and 'Restricted Access to Existing User'. Type the User's name to find them in the list and click OK. Remember this type of user has limited visibility and can not be assigned to work on Project Tasks.