Thank you for reaching out to us here on the Community page, @Vicky G.
I'm happy to share with you the steps on how you add those checks into QuickBooks. First, you need to recreate them manually by creating check transactions.
Here's how:
- Open your QuickBooks Online (QBO) account, then click Check from the (+) New icon.

- Fill in the required details then save the transaction.

- Replicate the steps for the rest of the checks.
For additional reference about managing checks in QBO, feel free to read the details from this link: Enter and write checks in QuickBooks Online.
Once they are cleared from your bank, you can now include them on your reconciliation. To learn about reconciling an account to match your bank/credit card statements, you may check out the instructions from this article: How to Reconcile an Account in QuickBooks Online.
Lastly, you can open the topics from our help articles in case you need related resources while working with QuickBooks in the future: Find articles, video tutorials, and more for QuickBooks Online.
I'm always here to help you out if you have any other questions. Just add a comment below. Have a good day!