Thanks for reaching out to me here in the Intuit Community, @christopher3.
Let's enable the two-step verification so you can get the code when logging in to QBO on your mobile phones.
To accomplish this, you'll need to login to the Intuit Online Account portal page to turn on the multi-factor authentication.
For more details with the solution above, please check this out: How do I enable or disable the opt-in two-step verification?
Should you need anything else with QuickBooks authentication, please let me know. I'd be glad to help.