A GPX or TCX from your watch — COROS, Strava, Garmin, Apple Health. Or a screenshot of whatever tracked it: Strava, Apple Fitness, Peloton, a tennis app, even the scoreboard. On Strava: open the activity on the website and hit “Export GPX” in the ⋯ menu (the app doesn't have it).
Any photos you took along the way. Drift reads where and when each was taken to pin it on the map — geotagged photos alone are enough to build a card from.
Anything the card should know — the score, who you were with, how it felt, or how you want it to sound.