As soon as you have the file ready, take note of the file location. Don't forget to add a bank account on your chart of accounts. Now, here's how you can load your transactions to QBO:
Go to the Banking tab.
Select Upload Transactions. This lands you to the Bring your info into QuickBooks page, click Browse.
Go through the file location then select the file.Click Open then hit Next.
Choose the right bank account and select Next.
This brings you to a new page, just click Let's go!.
You can use banking rules to easily categorize your transactions. Check out these helpful guides for more info: