Hello mail9,
No, we won't be able to remove the due date on an invoice. Setting a due date encourages your customers to pay within a certain period. You can use this article for reference: How to Create an Invoice.
If the customer directly pays the item or service, you might consider using sales receipt. Here's an article about this: Create Sales Receipts.
You can also consult your accountant for any professional advice about this. They can give you further explanation on when to use invoice or sales receipt.
Have a great day!