My Apple Account is not valid for password reset

If you’re seeing a message that the Apple Account is “not valid or not supported,” I’d first make sure you’re entering the exact email address or phone number used for that Apple Account.

If the account is locked or inactive, Apple may give you a “Request Access” option instead of letting you reset the password normally. Apple explains that here: If your Apple Account is locked, not active, or disabled - Apple Support

If you’re already signed in to that Apple Account on the iPhone, you can also try Settings > [your name] > Sign-In & Security > Change Password.

If the exact message is different, post the wording you see. That would help narrow it down.

If you can not reset your Apple Account password, you will have to use the Account Recovery process to get access to your Apple Account again.

Before you start this process, there are a few things to make sure of:

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• If you haven’t already, try to reset your password on a trusted device.
• If you don’t know which email address or phone number you use with your Apple Account, try different email addresses or phone numbers that might be associated with your Apple Account.
• If you don’t have a device that you can use, you can reset your password using the Apple Support appon a family member’s iPhone or iPad. You can also visit an Apple Store and ask to use a device.
• If you previously set up an account recovery contact, they can also help you reset your password.
• If you know your password, but don’t have access to your trusted phone number for verification codes, learn what to do.

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copied from: How to use account recovery when you can’t reset your Apple Account password - Apple Support