How to turn off two step verification in 2020

2 Step Verification or 2 Factor Authentication?

2 Step Verification 

How do I turn off two-step verification?

Sign in to your Apple ID account page.     

In the Security section, Click Edit.

Click Turn Off two-step verification.

Create new security questions and verify your date of birth.

You'll get an email confirming that two-step verification for your Apple ID is off.

Apple ID - Two Step Verifications FAQ.    

2 Factor Authentication 

From the article below updated on 22 Jan 2020. If it has been on longer than 2 weeks, you can't turn it off. 

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

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, however, you can unenroll for a period of 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 a higher level of security.

Apple ID -Two-factor authentication.       

Do you want to use two-factor authentication? You can turn that on, and two-step would be turned off. Make sure your set up can use two-factor though. See: Availability of two-factor authentication for Apple ID https://support.apple.com/en-us/HT205075 Turn two-factor on here: Apple ID: Your Account for Everything Apple  https://appleid.apple.com/#!&page=signin

They are two different authentication systems. 2 Step Verification was the first system Apple introduced. Apple then introduced 2 Factor Authentication, which is supposed to be more secure. The two articles explain what each requires.