Welcome to the Community, @wojtanowski26.
In QuickBooks Self-Employed, you only have the option to edit or delete the invoice and make corrections (see screenshot below). Right now, the ability to void a transaction is currently available in the Desktop and Online version of the product.
This is a great idea that will also benefit other customers. We take these suggestions as a guide on which area of the product we should enhance.
I’ll personally send feedback on your behalf about this feature for consideration in future updates. To keep you in the loop about the latest features being rolled out, visit the QuickBooks Blog page.
If there’s anything else I can help you with, click the Reply button and post a comment. I’ll be right here ready to help you. Have a good one.