KSA E-Invoicing QR Code for POS

Not a perfect solution, but this app can be used for the time being to generate QR Code in the POS Invoice.

Meanwhile, you can comment/react/contribute to this pull request(feat(Regional): KSA E-Invoing optimizations and POS support by rtdany10 · Pull Request #28776 · frappe/erpnext · GitHub) for a better solution.