Lost phone
My son lost his phone and Icloud is requiring his phone as part of the two party login, How can he login to Icloud and locate his phone. In case you think there is no valid excuse, he did drink a lot at last nights wedding.
He doesn't need a two-factor code. He can use any internet browser and log into www.icloud.com/find without a code.
Also see: If your iPhone, iPad, or iPod touch is lost or stolen - Apple Support