An invoice is a document your customer keeps. It should carry your layout and your details, not a generic template you cannot change.
Build the Document
Header, line items, totals, adjustments and footer are blocks you arrange, with control over fonts, spacing, alignment and width.
PayNow QR on the Invoice
A PayNow QR code can be placed directly on the invoice, so a customer pays by scanning the document they were sent.
Separate Templates for Separate Jobs
Invoices and receipts are designed independently, because what a customer needs when paying is not what they need as proof afterwards.