Receive verification code via WhatsApp?

When I travel abroad, I buy a local SIM card, and rely on WhatsApp for international messaging. At those times, I don't have access to my US phone number, a Consumer Cellular account. For two-factor authentication, Apple wants me to enter trusted phone numbers. So, how do I manage things so that Apple will send me verification codes via WhatsApp, either all the time or (preferably) when I notify Apple that I am traveling abroad?