I missed an expense item when reconciling How do I add it?

I'll share with you the two options on how you can add a missing expense to finish your reconciliation, @khardwick7.

You can create an expense either in the + New menu or directly to your register. Before that, please click Save for later in the Reconcile screen to initially save the changes (see the screenshot below). 

Here are the steps for the first option: 

1. Go to + New from the left menu. 
2. Select Expense under Vendors. 
3. Enter the necessary information. 
4. Make sure the Payment date is within the period you're reconciling. 
5. Click Save. 

To learn more about this process, go through this article: Enter, Edit, or Delete Expenses. 

For the second option: 

1. Go to Accounting from the left menu. 
2. Select Chart of Accounts. 
3. Locate your account. 
4. Click View register from the Actions column.
5. Choose Expense from the Add transaction drop-down. 
6. Fill in the necessary fields. Make sure the date is within the period you're reconciling. 
7. Click Save.

The screenshot below shows you the last three steps. For detailed instructions, check out this article: Add Transactions To Account Registers. 

Once done, reconcile your account again. 

I'd suggest visiting this website: Reconcile Workflow. This link provides you more details about starting, fixing any differences, and completing the reconciliation process. Just click the link beside QuickBooks Online on every scenario. 

I'm just a post away if there's anything else you need. Have a great day, @khardwick7.