How can i disable two-factor authentication?

You can only turn it off if it has been less than 2 weeks since you turned it on.

You shuld be able to sign into iCloud with two factor as long as you can recive SMS to your trusted phone number.

So talk to you r carrier and get a new sim and you shuld be good.

Two-factor authentication for Apple ID - Apple Support

"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, you can unenroll within two weeks of enrollment. 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."

Good luck!

Visit the cellular service give your identification proof and issue a sim on behalf of the same number and insert the sim https://support.apple.com/en-in/guide/iphone/iph3f11fba92/ios in new iPhone that is purchasedhttps://support.apple.com/en-in/guide/iphone/iph1fd7e482f/ios

The Apple ID and password is active so is the 2FA active on the iCloud server , once a new trusted number is added the code will start appearing on the new trusted number , and the person can access the account , by sign in with Apple ID and password .

https://support.apple.com/en-in/HT204974

Note : once 2FA is activated in latest version of iPhone / Mac it can't be disabled