Workspace membership grants access to the workspace. Project membership is separate: you add teammates to specific projects so they can collaborate on that deal. Teammates must already be members of your workspace before you can add them to a project.
Add someone to a project
Open the project's members panel from Settings → Projects, or from the project itself.
Search for a workspace member by name or email, or invite a new teammate by email.
Pick an access level.
Click Add.
Project access levels
Can edit: Upload files, start conversations, and run workflows in the project.
Can view: View files and shared conversations. Cannot edit or converse.
The project also has an Owner: the person who created the project. The Owner cannot be changed from this panel.
If you need to manage members of a project, you need to be the project owner, or a workspace owner or admin.