I'd be delighted to address your concern about integrating your Stripe account with QuickBooks Online.
You mention that the transactions are already synched on your QuickBooks Online account. If you want to remove them, the only option we have now is to delete them manually. Here's how
Go to the Sales or Expenses menu.
Find and open the transaction.
Review the transaction. Make sure you need to void or delete it.
If you want to include the void or delete date, add a note to the Memo or Message section.
Select More in the footer. Then select Void or Delete.
Select Yes to confirm.
You can only void one transaction at a time. Since the change is permanent, QuickBooks limits how many you can void to prevent mistakes.