Use the staffed ticket window or ticket machine if available, try another payment method once, and switch to taxi or ride-hailing if the metro task is blocking the next move.
Do not assume every metro app flow accepts foreign cards.
Do not assume cashless ticket machines always have English.
Do not block an urgent trip for app setup.
Traveler experience
Watch and read real traveler context
These videos and Reddit threads are related to this guide's scenario. Use them
as practical context, not as a guarantee that the same steps will work for every
card, device, passport, hotel, route, or merchant.