To sign in to an existing Medium account using "Sign in with Apple," the email address associated with your Apple ID MUST match the email address associated with the Medium account you're trying to sign in to. You will NOT be able to sign in to an existing Medium account if you opt to hide your email address during the Sign in with Apple flow.
There are 2 ways to resolve this issue:
Sign in to your Medium account using the method you used to sign up, and do not use "Sign in with Apple."
Choose to "share your email address" during the Sign in with Apple flow. If your Apple ID email address matches the email address on your Medium account, it will connect automatically. You will then be able to use Sign in with Apple going forward.
To do this, follow the steps below:
- Open your iOS Settings app
- Select the top option where your name is displayed with Apple ID, iCloud, iTunes & Ap... beneath your name
- Select Password & Security
- Select Apps Using Your Apple ID
- Select Medium
- Select Stop Using Apple ID
- Go back to the Medium app on your device
- Select Sign in with Apple
- Select Share My Email