I want to turn 2 factor authentication off

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.

After you set up iPhone, you can adjust accessibility settings.

• Go to Settings > Accessibility.
• Choose any of the following features: Vision. VoiceOver. Zoom. Display and text size. Motion. Spoken content. Audio descriptions. Physical and motor. AssistiveTouch. Touch accommodations. Back tap. Reachability. Call audio routing.

Get started with accessibility features on iPhone - Apple Support

As explained in the support document you posted from ,If the Apple ID is brand new, it cannot be turned off.

If it was an older Apple ID that had turned it on, on less than 2 weeks ago, you can use the link in the enrollment email you got when turning it on, to turn it back off.

With that said, 2 Factor authentication applies only to the Apple ID, and will be transparent in every day use of the iPhone. They should not have to deal at all with 2 Factor authentication in normal operation.

You can't.