How can I turn off two authentication, it’s not say turn off

2 Factor Authentication

Two-factor authentication for Apple ID

If you already use two-factor authentication, you can no longer turn it off. Certain features in the latest versions of iOS and macOS require this extra level of security, which is designed to protect your information. If you recently updated your account, you can unenroll for two weeks. Just open your enrollment confirmation email and click the link to return to your previous security settings. Keep in mind, this makes your account less secure and means that you can't use features that require higher security.

https://support.apple.com/en-in/HT204915

I'm afraid the inability to remove 2FA apparently also applies to phones where it comes ready enabled - the two week window applies only where you turned it on yourself - so you won't be able to turn it off.

I'm afraid not.

Hello. You can’t turn off TFA as it is at the highest left of security.

May I ask you why you would like to turn it off? You are not receiving codes in your country?

Unfortunately you can’t turn it off. There are other features in iOS 13 where you can monitor your kids.

Spying on kids is bad.

Like Screen Time.