Three Ways to Transfer Ownership of Google Sites
Click the 'Share with others' button at the top of the menu, add the email address of the person you want to transfer ownership to, and choose 'Transfer ownership' from the drop-down menu. Ownership request invitations will then be sent to that user, and ownership will be transferred upon acceptance.
2. Transfer via Google Shared Drives.
But the problem in this method is that Shared Drives are only available on Google Workspace Business Standard or higher editions. Therefore, we are left with next option as our last resort.