If your foreign customers register their companies in China, then sales will definitely occur. If your foreign customers are originally abroad, there are customs declarations, packing lists, proforma invoices and contracts at the beginning of export, and your payment must be transferred to your foreign currency account in the form of foreign exchange. You need to go to the bank to settle foreign exchange. If the other party needs an invoice, it can make a proforma invoice or issue an invoice for export commodities.