Welcome to the Community. I can provide clarification about how the QuickBooks Bank Feeds feature works.
When you link a bank account, QuickBooks downloads your bank transactions automatically. Some banks let you download the last 90 days of banking data, and others can go back as far as 24 months.
The range of transactions will solely depend on the bank or financial institution. To bring older data into QuickBooks, you'll need to download statements from your bank's website and upload them manually.
On the left navigation bar, click Banking.
Select the bank account.
Press the Linkaccount drop-down, then select Upload from file.
Upload the file and click Continue.
Choose the bank account you've created in QuickBooks.