Let me share some information about the batch delete option.
In QuickBooks Online, we can batch-delete invoices. However, this isn't an option if the invoices were coming from any third-party apps. In the meantime, you can delete them one by one by following these steps:
Go to Sales and select the Invoices tab.
Find the transaction. In the Action column, select the small arrow icon and select Delete.
You can also open the transaction and delete it. In the Action column, select the small arrow icon and select View/Edit.
Select More in the footer. Then, select Delete.
You can also look for an app that helps delete transactions in bulk. QBO supports thousands of various third-party applications for any functionality you may need. Head to the Intuit App Center and type a keyword in the search bar.