Two factor ID via email

There is no option to have an Apple two-factor code sent by email. It will be automatically sent to all of your trusted devices. You can also request it be sent to a trusted phone number. It is highly recommended to set up more than one trusted phone number (they can be iPhones, Androids and/or landlines).

To set up trusted devices and trusted phone numbers, see the "About trusted phone numbers and trusted devices" section of Two-factor authentication for Apple ID - Apple Support

If you need to get the code sent to a trusted phone number via text or phone call, see: Get a verification code and sign in with two-factor authentication - Apple Support

Another option is a Security Key (e.g., YubiKey). See: About Security Keys for Apple ID - Apple Support

Apple does not send verification codes to e-Mails. (it’s WAY too vulnerable security-wise)

However, the functionality you’re seeking IS provided by “Trusted Numbers.”

These are numbers which you pre-designate to receive the code; which can be delivered via SMS or voice calls to virtually any number on the PSTN.

NOTE: Your iPhone is a Trusted Device … it should generally NOT be a Trusted Number to your own AppleID.

Two-factor authentication for Apple ID - Apple Support

Get a verification code and sign in with two-factor authentication - Apple Support

All of your possible options to receive - or self generate - a code are outlined in this article:

Get a verification code and sign in with two-factor authentication - Apple Support

How do I get another two factor verification code