Check the latest requirements for the chosen payment instrument, try to bind a suitable bank card, and test it with a small transaction upon arrival.
Don't wait until you're waiting in line
Before paying for your train ticket or dinner, download the app in advance, complete verification, and save key pages. The internet makes the process slower than you might think.
Prepare practical alternatives
Wildcards and cash are used differently at different locations. Bring a small amount as a backup and ask the hotel for the latest local advice if the application expires.