Apple creates a unique e-mail address (it is something like xy2dnsAd@privaterelay.apppleid.com )for you and you'll need to find that for us to update your access. To obtain your “privaterelay” email address from Apple:
Please sign into https://appleid.apple.com using your Apple ID and then go to Security -> Apps & Websites using Apple ID -> Manage -> Hallow and see what it says for “This App Received”. I’ve pasted some screenshots below of each step just in case this is helpful. Once you find your privaterelay e-mail please let us know what it is and we can go from there!