Upload the Rate Confirmation to Google Drive, right-click it → Share → set to "Anyone with the link".
To replace it later: right-click the same file in Drive → Manage versions → upload the new file. The link on this page stays the same — nothing to edit here.
Only if you want to change the link itself: open index.html in your hosting File Manager (Edit), find the line marked GOOGLE-DRIVE-LINK, and swap in the new link.