.Hi there, calfeepm-gmail-,
QuickBooks will only download transactions within the last 90 days, the rest can be imported using a web connect file. Please follow the steps in this article: Manually upload transactions into QuickBooks Online.
If you'll be using a CSV file, you'll want to format it to be sure you can upload the transactions. Please refer to this article: Format CSV files in Excel to get bank transactions into QuickBooks.
Let me know if you have other concerns.