We deprecated Classic Sites Manager and migrated classic Sites to new Sites.
Your classic Sites are automatically downloaded as a Takeout archive and saved to your Google Drive.
Some have been replaced with drafts in the new Google Sites experience for you to review and publish.
If your Workspace account belongs to an organization and you can’t find Takeout in your Drive or need help with the converted draft site, contact your domain admin to access the takeout of your classic site or get details about the converted site.
Learn how to download data from Google Takeout.