Some banks would require Multi-Factor Authentication (MFA) credentials when manually updating the bank connection in QuickBooks Online, quickmicks1207.
Can you confirm if you're reconnecting or manually updating an existing bank account? If so, it's an added security precaution that requests more than a single username and password. It's designed to protect your financial information from unauthorized access and potential fraud.
If not, can you also tell us what type of details were asked and if you received the prompt inside QBO? We're asking these questions to make sure we provide the most accurate information to sort this out.
In the meantime, I suggest reaching out to your bank to also confirm the legitimacy of the request, especially if you see it outside of QBO.
For additional guidance when using the Online Banking feature, I'll share these articles with you: