You need to create a project by creating a project or have already joined a project. For ordinary projects, the project creator (responsible person) and members within the project can add their friends and CAD Viewer users to their respective projects.
[Step 1]
Click "Project" to enter the project list, select a project.
[Step 2]
After entering the project, switch to the "Project Members" tab and click the Add Member button to enter the Add Project Member
[Step 3]
On the Add Project Member page, you can choose to add people to the project through Search, Cell phone address book, or CAD Viewer friends, etc. You can add people to the project without verifying them, so you can add them to the project directly.