Michael, via a phone call or different device. But we're talking about the case, which must encompass many if not most Apple users, of having more than one device!
That support page says this:
”How it works
With two-factor authentication, your account can only be accessed on devices you trust, like your iPhone, iPad, or Mac. When you want to sign in to a new device for the first time, you'll need to provide two pieces of information—your password and the six-digit verification code that's automatically displayed on your trusted devices. “
OK, my iPad is a trusted device. It should let me in without any authentication. If it's considered not trusted, it shouldn't receive the code!
What's a trusted device?
”Trusted devices
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.”
Well, If I’ve already signed in using two-factor authentication, why is it requiring me to sign in again?
And, if I’m not signed in, why is it sending the code to a non-trusted device? As Spock would say, “Highly illogical, Captain!”
It further says this:
”When you sign in on the web, you can choose to trust your browser, so you won’t be asked for a verification code the next time you sign in from that computer.”
Yet, even after trusting the browser, it keeps asking for verification the next time I sign in on that computer!
In other words, it's not working the way that page says it should!
——
Clearly, we have a failure to communicate here. You all seem perfectly content with however it's working — and probably stay logged in all the time with your Apple ID — so, it's not a problem for you and doesn't interfere with your use on an iPad.
But it does interfere with mine, which is why the issue arose. Yet, the real problem is that it doesn't fit any model of security I've ever encountered or what I’ve read about 2fA.
If what I’m experiencing is how it's supposed to work, which is contrary to what Apple's own web page states, then I'll just turn it off as it's offering me no extra security, at all!
In any case, I’ve wasted enough time here on this and am not getting any coherent explanations but rather patronizing or tangential responses, so I’m done. Thanks for trying, anyway!