In Phase 2 of e-invoicing (integration), an invoice has to be signed with your business's certificate and sent to Fatoora, the platform of the Zakat, Tax and Customs Authority. Every return needs a credit note that points back to the original invoice, not a void that disappears from the system. A restaurant issues hundreds of invoices a day, so anything manual in that chain gets late or gets lost.
In Loqma, the invoice is part of the sale itself: it is issued when the order closes, a return issues its own note, and reporting to ZATCA happens in the background. The cashier sees none of it and is never slowed down by it.