cms_content_sync-3.0.x-dev/modules/cms_content_sync_private_environment/cms_content_sync_private_environment.links.task.yml

cms_content_sync_private_environment.private_environment:
  title: Private Environment
  route_name: cms_content_sync_private_environment.private_environment
  base_route: cms_content_sync.site
  weight: 10