This update integrates Viettel SInvoice, enabling Point of Sale (PoS) systems to automatically generate and attach e-invoices compliant with Vietnamese regulations. The changes improve the PoS system's ability to meet local tax requirements and streamline the invoicing process for Vietnamese businesses. A key technical update involves extracting invoice file retrieval logic for reusability and improved accuracy.

Add Viettel SInvoice integration with the Point of Sale module to support PoS e-invoicing for the Vietnamese market.

task-4844619