How can I disable two step verification

2 Step Verification or 2 Factor Authentication?

2 Step Verification

How do I turn off two-step verification?

1. Sign in to your Apple ID account page.
2. In the Security section, Click Edit.
3. Click Turn Off two-step verification.
4. 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.

Two-step verification for Apple ID - Apple Support

2 Factor Authentication

From the article below. 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

I suspect you may be using the newer two-factor authentication rather than the older two-step verification.

The following has information about two-step verification (ignore the part about switching): Switch from two-step verification to two-factor authentication - Apple Support

However, if you are using two-step authentication, see the following from Two-factor authentication for Apple ID - Apple Support

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.