2) If no .QBO file available, then the next best choice is a CSV file… you can open that in Excel and do some interesting cleanup work with will help immensely during the import process. QuickBooks Online will let you import a CSV file, but restricted to 3 columns: Date, Payee, Amount (missing NUM and MEMO; which is a BIG issue!) But, you can use CSV2QBO
(a $60 software) to make the excel/CSV File import into Bank Feeds / Downloaded Transactions in QuickBooks Online
as a QBO/Webconnect File with all the fields.
These are NOT easy concepts, you may need to watch this 1 hour video to understand the mechanics:
If you want private one-on-one training on how to do this, you can hire Hector for $500, the training will last about 90 minutes, and he can help you do you first import with you.