This support article has a list of things to do if your iPhone, iPad, or iPod touch is lost or stolen. --> If your iPhone, iPad, or iPod touch is lost or stolen - Apple Support
It sounds like you are using account recovery. From: How to use account recovery when you can’t reset your Apple ID password - Apple Support
"In some cases, you might be able to speed up the account recovery process or reset your password immediately by verifying a six-digit code sent to your primary email address. You might also be able to shorten the wait time by providing credit-card details to confirm your identity. If you’re given this option, an authorization request goes to the card issuer." - see the document for more details.