Welcome to the QuickBooks Community, Marc-Andre!
I'd be happy to provide some information on how to download bank transactions.
Some financial institutions have limitations on the date range for downloading transactions when you connect your bank account to QuickBooks. While some offer 30-days, others may offer 90-120. However, you can manually import transactions by following the steps in this link. I also recommend browsing through this article on how to correctly format CSV files in excel to get bank transactions into QuickBooks.
If you have any other questions, please don't hesitate to reach back out here.