I entered a couple of items in the sales invoice but it is showing that they are still due. How do I update this status?
I don’t understand what you mean. Please place screenshots to clarify your question.
Show the edit screen of the Receipt transaction
That is not the receipt. It is the sales invoice. You were asked to show the Edit screen of the receipt. Did you enter one?
As a new user please start by reading the current Guides and the new Guides in progress to make yourself familiar with how the application works.
The sales invoice creates a receivable (the obligation). A receipt is necessary to record receiving the money.
Because that is their status. The first 3 invoices were issued on April 2nd. Today is April 3rd. So they were due yesterday. (If you do not enter a specific due date, which you did not, the program uses the issue date as the due date. That is clearly explained in the Guide, if you had read it as suggested.) The most recent 2 invoices were issued today, so they are due today.
Is it possible you were confused by the date format? That is also selectable, as is also explained in the Guides.
By entering a receipt against each of these invoices. Is the basis of accrual and double entry accounting. The invoice will show an amount as income but that amount is still to be paid by the customer. Only when you assign a receipt to the invoice (use view screen of that invoice and click on new receipt) with the so called accounts receivable (See @Tut answer) be cleared and so will the invoice. The amount on the receipt will not be added to the income as the receipt is against an asset (accounts receivable).
I think tlhpeople has entered bank transactions (receipts) as sale invoices, when they should have been entered as cash sales