Hello, mccandlesscontra.
Thank you for coming to the Community with your question about downloading bank transactions. I'd be happy to show you how to get more than 3 months worth of activity in your account.
Historical bank activity can be exported from your bank website, then uploaded into your QuickBooks Online account. The first step in this process is to download the transactions from the bank in a QB Online supported file format. I've got a great article that will walk you through, step-by-step. You can check it out here: https://quickbooks.intuit.com/community/Banking-and-bank-feeds/How-to-upload-more-than-90-days-of-ba....
I wish you and your business continued success. Feel free to reach out to me here if you have any other questions.