how to turn off two-factor authentication?
can two-factor authentication be turned off?
No, it is required by Apple for use of an AppleID.
Two-factor authentication for Apple ID - Apple Support
”If you're already using two-factor authentication with your Apple ID, you can't turn it off. 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.”