Hi Rob,
You’re currently able to do this in ‘Classic’ view, as this functionality hasn’t yet been rebuilt in ‘Beta’ view. Toggle to ‘Classic’ view using the toggle in the header, then ‘issue and email’ the invoice where you’ll also be able to edit the email text. Our dedicated Help article explains how to do this: https://help.crunchfree.co.uk/s/article/How-to-create-a-sales-invoice-in-Crunch-Zero
“Payment due by: Pending” means the invoice hasn’t been issued yet. Once the invoice has been issued the date will appear here, using the payment terms you’ve set.
I hope this explains everything you need!