PIN for second user

I got you covered in turning off the authentication when logging into QuickBooks, @thellen.

The multi-factor authentication is an additional layer that strengthens the security of your QuickBooks Online account. And turning this off affects all users. If you want to turn it off, you can follow the detailed steps below:

1. Log in to the Intuit Online Account management portal.
2. Select Sign In & Security from the left menu.
3. In the Two-step verification section, click Turn off. 
4. Enter the code.
5. Click Continue.

If you're using a different phone number, you'll need first to update your phone number so you can log in to the account. Once done, you can now turn off the two-step verification.

For more information about this process, look at this article: Turn on or turn off two-step verification.

For additional reference, here's an article which you may find helpful: Add and manage users in QuickBooks Online.

If you need more help, let me know by commenting below. I'm always here to answer it. Have a nice day.