It's important that you have all transactions entered in your books to make sure that your accounts are well balanced. Quickbooks Online has the ability to connect to various banks in order to import transactions to save you time with data entry. I can provide some assistance with connecting your accounts.
When it comes to connecting QuickBooks Online to a bank account, there are many different options to connect to a Desjardins account. You can see them all by searching for Desjardins in the search bar that appears after clicking on the Link account option. If you have a business account with Desjardins, make sure you're using the option specified for business, and the same for personal bank accounts. Different options require different sign-in info, so make sure you're using the correct one.
If you have any other questions, feel free to reach out here.