Turn the scene's public link on or off and return the link.

Anyone with the link can open the scene without signing in:
- `view` lets them view it
- `edit` lets them edit it
- `none` turns the link off

This is the link from the scene's **Share** dialog. When the link is turned on, guests can also read and write comments; turning it off removes their access.

<Callout type="warn">
Turning the link on fails with 403 when a workspace admin has disabled scene sharing for the workspace.
</Callout>

**Use cases:**
- Sharing a diagram with people outside the workspace
- Letting guests edit a scene
- Revoking public access to a scene