Glad to see you here, tcardreon.
I can help you with resolving the error you've encountered when importing the transactions to your QuickBooks Online account.
Each bank formats its CSV files differently, so you'll need to edit the CSV file first for it to be imported successfully to your account. You can use either a 3-column or 4-column format.
The 3-column template has columns for the Date, a Description of the transaction, and the Amount of the transaction. The 4-column template has a Date column, a Description column, and both a Credit and a Debit column. I'll be adding a screenshot below for your reference.
Here's more information on how to import bank transactions using Excel CSV files.
That should help you fix the error. If you have any other questions or would like me to clarify anything else, let me know. I am always glad to help in any way I can. Have a good day.