Make your account private

1. Open Settings → Privacy.
2. Turn on Private account.

What changes

• New followers must be approved. Requests appear in the notification center and on your profile.
• Your posts, clips and stories are visible only to approved followers.
• You are left out of discovery: search shows your name and username but nothing else, and you do not appear in For You or Nearby.
• People you already follow, and who follow you, keep their access.

Turning it off makes your account public again. Pending requests are approved automatically.