/creator-studio/projects/all?tab=trash. Moving a project there is a soft delete. It just leaves the main views, and a trashed project can’t be opened into the editor until it’s restored.

Deleted projects, waiting to be restored or cleared
Workspace viewers can’t open Trash at all. The tab is locked for that role. Managing a project’s trash lifecycle (moving it to Trash, restoring it, or removing it from Trash) is limited to the project’s own owner or the workspace owner; other members can’t act on a project they don’t own.