Set project visibility to team-wide or invitation-only.
Prerequisites
Project ownership
Steps
Step 1: Open Share Settings
Click "Share" button, then click "Invitation only" in the Access section.
Step 2: Select Access Type
Click the Access dropdown and choose:
Team: All organization members can access
Only invited people: Restricted to invited users
Step 3: Save
Click "Save" to apply changes.
Access Types
Team Access: Visible in team project lists
Invitation Only: Hidden from non-invited users