The Stryd app does not capture or calculate any calorie information.
When you export your data to platforms such as Strava, you might see calorie-burning information, which is calculated by Strava on their end (it does not originate from Stryd).
If you record Stryd data on your watch, then you may see calorie information in your watch app. Stryd does not import this information into our system.
Other apps, such as FinalSurge, rely on calorie information within the FIT file passed to their platform, which is why the calorie burned information may remain zero if you import the Stryd file to another platform.