how do I turn off two-factor authentication?

Hello manasarovar,

Two-factor authentication is enabled by default on new Apple IDs and cannot be turned off.

If you have an older account where you only very recently activated Two Factor Authentication, note this section of the Apple support article -->

"If you updated to two-factor authentication inadvertently, you can turn it off* within two weeks of enrollment. If you do, your account is less secure and you can't use features that require a higher level of security."

Read the details about doing this in the document: Two-factor authentication for Apple ID - Apple Support

The part actually telling you how to unenroll if you still can is, uh, oddly omitted from the newer version of the support article. Here's what they removed: "Just open your enrollment confirmation email and click the link to return to your previous security settings." I'm putting this in a separate post because since it has been deleted it is now likely considered unsubstantiated lore. ;-)