Last December, the financial services giant Paypal finalized a deal that allows the American company to formally enter China’s fast-growing mobile payments market, which is now dominated by home grown behemoths WeChat Pay and Alipay. China had long promised to open up the market to foreign competition, and Paypal became the first foreign firm licensed to provide digital payment services in China by acquiring a 70 percent stake in GoPay, a domestic Chinese payments company with a license to