There are easy steps to resolve this. You have to leave the window open that asks for your verification code open, or it will invalidate the code. But, when you check your e-mail on the same device it sometimes closes the window.
I recommend opening a separate browser for your email and then a new browser for your TurboTax account. Then make sure you have deleted all previous code request emails so that the next one is the freshest.
https://ttlc.intuit.com/replies/4576376
Here is a way to get your 6 digit code from TurboTax for multi-factor authentication. Texted to you:
please only call my land line, not verification to e-mail
please call my land line for verification not my e-mail
We cannot set up a call on this public forum. If you are having trouble with your verification code, please see the Help Article here for further assistance.