If you have logged in to Goodnotes with a "Hide My Email" address, e.g. xxx@privaterelay.appleid.com, the Account Info page will show that email address, which can't be edited in the app as the info is retrieved from the Apple account.
Important: These steps is applicable exclusively for iOS only users. Do not proceed if you are using Goodnotes on Android/Windows/Web. Deleting your account on iOS device will result in the removal of associated data and subscription purchased on these platforms.
To get the app to show the actual email address of your Apple account, please take these steps:
- Delete the current Goodnotes account.
- Open device Settings > Apple ID > Password & Security > Sign in with Apple > Goodnotes > Stop Using Apple ID.
- Sign in to Goodnotes again with "Sign in with Apple", this time not choosing the "Hide my Email" option. The Account Info page should show your real email address.
- If previously on the yearly plan, re-subscribe to it by choosing Subscription Type > Resubscribe (*).
(*) Not applicable if you're on the free or one-time payment plan.
See also: Why am I getting "Subscription detected from App Store"?