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How do I get my photos back from my old IPhone if it keep saying “Invalid Email Address”
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You need to be signed into the same Apple account (ID) on both devices. Typically an Apple ID is an email address you have used. If you are currently using a mobile device that is logged into your account, go to Settings and tap your name at the top.
This support article describes ways to find your Apple ID --> If you forgot your Apple ID email address or phone number - Apple Support
or go directly to this link --> https://iforgot.apple.com/password/verify/appleid#
If you still need help:
Contact Apple for help with Apple ID account security "This article provides country-specific Apple Support contact information for customers seeking help with their Apple ID password or other security-related issues."
Contact Apple for help with Apple ID account security - Apple Support
Also look in Keychain, and in a browser's security settings if you use it to automatically sign into Apple when using a browser.