Support and bug reports
If something is wrong in the app, the useful things to include are your iPhone and watchOS versions, the app version, and what you were doing when it happened. A screenshot usually saves a round of questions.
Feature requests
Worth sending. Say what you are trying to find out about your game rather than what button you want — the underlying question is usually the more interesting half.
Privacy questions
What the app collects and what happens to it is set out in the privacy policy. Anything it does not answer, ask directly.
App Store
Ratings and reviews go through the App Store listing: Padelistics: Padel Tracker on the App Store.