Hi there, @Babawonga.
QBO allows integration with Vend POS to download transactions. Some payments will appear in your Vend register, while some of it won't match the corresponding QuickBooks Online transaction.
Also, I'd encourage you to reach the Vend Support so that they can assist and inform you of what transactions can be matched in QBO.
I've added a handy link as a reference so that you can quickly navigate to their support site: Vend Help Center.
Also, once you know what transactions you can pair in QuickBooks transactions, you can then match the Vend POS entries in QuickBooks.
Please let me know how it goes so that I can assist you as fast as I can. Stay safe and well!