iCloud login
Late model iMac that is having getting logged back into iCloud. I put in my Apple ID and password and then it wants a verification code sent to my iPhone which never comes. What is going on?
iMac Pro
Get a verification code and sign in with two-factor authentication - Apple Support
You need another trusted device or telephone number.
See Two-factor authentication for Apple ID - Apple Support:
A trusted device is an iPhone, iPad, or iPod touch with iOS 9 and later, or a Mac with OS X El Capitan and later that you've already signed in to using two-factor authentication.