Yes, you can match your previous bank transactions. You'd want to make sure that your bank transactions are recorded in QuickBooks. I can guide you on how to do it.
Go to the Banking menu.
Choose the Banking tab.
From the For Review tab, you can see the list of your downloaded bank transactions.
Hover to the Category or Match column, click on the 1 record found prompt.
Click the Match link.
Just a heads-up, the system will be able to automatically detect match transactions especially if it has the same transaction dates, amount, and payee information. If QuickBooks was not able to find a match, just click on the Find Match radio button. You can read through this article for more detailed steps: Categorise and match online bank transactions in QuickBooks Online.
I've added these articles to help you manage your downloaded bank transactions: