I deleted a transaction my mistake. How can I restore it? Thanks

Hello, topgun18. 

Welcome to the QuickBooks Community. We won't be able to undo a deleted transaction. However, we can review the Audit Log to see the details and recreate it manually. Here's how: 

1. Click the Gear icon and select Audit Log. 
2. Look for the deleted transaction and click View. 
3. Tap the arrow on when it was created and deleted. 
4. Take note of the transaction details. 
5. Recreate the transaction manually by clicking the Create menu (+ New). 

After we recreate the transaction, we can go back to your for review tab and categorize the transaction. You can use this article for the detailed steps: Categorize and match online bank transactions in QuickBooks Online. 

That's it. This should help you point in the right direction. Let me know if you have further questions. I'll be here to answer them. Have a great day!