Let me help you record your sales transactions in QuickBooks, @bravofoodsltd.
Sales can be recorded by creating a sales receipt for an immediate sale or by creating an invoice for billing a customer and to record an accounts receivable sale.
If there is a prompt that shows "Please enter valid email address, or clear the Send later checkbox", this means that the Send later box was checked. We can simply uncheck the box so you can record the transaction.
However, if the prompt tells you that "Please add the customer's email address to share this invoice's link", then you can simply click the drop-down button beside the Save button and select either Save and new or Save and close to record the transaction.
You can also run reports in QuickBooks Online to get a snapshot of various aspects of your business. You can filter these reports to set custom criteria for the transactions, then memorize them to save its settings.
You can always drop a comment below if you need anything else. I always ready to help.