How to disable two factor authentication?

Sorry, it is not possible, see this Apple article: Two-factor authentication for Apple ID

Two-factor authentication for Apple ID – Apple Support (UK)

👉 Can I turn off two-factor authentication after I’ve turned it on?

If you are already using 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 have recently updated your account, you can unenrol within two weeks of enrolment. Just open your enrolment confirmation email and click the link to return to your previous security settings. Bear in mind that this makes your account less secure and means you can't use features that require higher security.

Not going to happen; 2FA is here to stay.

Suggest you learn more about 2FA from the articles linked below.

Pay particular attention to setting-up your trusted numbers; they become CRITICAL if you loose access to your trusted devices.

They should NOT be the number of your mobile device (it receives verification codes automatically)

Also consider setting-up a Recovery Contact.

Two-factor authentication for Apple ID - Apple Support

Get a verification code and sign in with two-factor authentication - Apple Support

Set up an account recovery contact - Apple Support