With less than a month to go before kickoff, and the event already encumbered by diplomatic boycotts and the threat of virus outbreaks, China is looking to use the games to showcase the digital yuan’s clout globally. Visitors can download an app or get a physical card that stores the digital yuan, or convert foreign bank notes into e-CNY at self-service machines, according to the Bank of China Ltd., a state lender and official partner of the games.