Hi there, @boruchw,
You'll be glad to know that you can correct the classification of an entry.
To do so, let's first change the label of the item on the Products and Services page. Here's how:
Then, edit the entry on your register to correct the classification of the account. Let me guide you through on how to accomplish this.
Moving forward, QuickBooks will recognize the Retained Earnings as the Income account for that item.
Feel free to read through this article for the detailed steps: How to add or edit transactions in a Register. This link will guide you on how to change the entry details on your Chart of Accounts.
Keep me posted if there's anything else you need with correcting entries in QBO and I'd be glad to help.