The short answer is no.

When POS is joined to the QuickBooks accounting, POS takes over the inventory.

It posts its sales to the accounting software.

If you generate sales of items on the accounting side, POS will not see them. This will throw off your inventory qty, amounts, costs.....

You have to do the sales through POS and use the payment method of Charge on Account. That will create an invoice in QB.

They can receive the A/R payments on the QB side, because the POS and QB exchange A/R account balances on the customers.