You need to be a workspace owner or manager to change member access permissions.
Check or modify project members from within a project
From the project home page, you can check the workspace members who have access to the project.
From this page, you can manage members:
Add existing members if they don't already have access. In the screenshot above, the owner and the manager have access to the project by default.
Remove members with a user role.
Change user permissions within the project by switching between viewer and editor permissions.
Remember, you can only add existing members to a project. If you need to add a new member, they must first be invited to join the workspace in the workspace member settings.
Modify members from the workspace level
You can add or remove members from a project, as well as change their permissions, in the workspace member settings.
Click on the three dots at the end of a member's row and choose Manage access.
Remove a project from this user by clicking on the trash bin.
Add a project by clicking on +Add projects and choosing the projects you want to add.
Modify their role within a project using the drop-down menu.
Save any changes.