Hello there, @evann-wehman.
Allow me to provide two ways on how to deleting or voiding the invoice.
First, if you create the invoice within QuickBooks Online (QBO). You'll have the option to delete or void the transaction from the invoice list. Let show you how to do it.
- Go to Sales from the left panel. Then the Invoices tab.
- Select the invoice and click it to expand the page.
- Choose More button at the bottom of the page.
- Hit the Delete or Void.
- Select Yes to confirm.
However, if you're using a third-party app when creating the invoice, I'd recommend reaching out to the third-party web store provider. From there, they can guide you in the process of removing the invoice.
I've attached this article about customizing form templates in QBO, check out this link: Customize invoices, estimates, and sales receipts in QuickBooks Online.
In case you want to send and print your invoices in the future, open this article for your reference.
Please touch base with me here for all of your QuickBooks needs, I'm always happy to help. Have a good one.