This Apple Account is not active.

I believe this is the message displays when an Apple Account with legacy account security (security questions) becomes locked (e.g. from two many incorrect password attempts, etc).

Two step verification launched in 2015 and you have likely received pop-ups when you sign into a new iPhone or often when you update your iPhone that inform you that it is strongly recommended to upgrade your account security and you have to opt-out to bypass that warning.

Two-factor authentication for Apple Account - Apple Support

I don't believe there is any action that can be taken outside of contacting Apple Support.

Contact - How to Contact Us - Apple

Click here and contact Apple Support. If the linked method won't work in your country, pick one from this document.

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