Write to hello@orbinauts.com.
That address is the right one for anything:
- a pass time that turned out wrong, with the city or the coordinates and the time you expected;
- a question about the API, or a problem with it;
- a city you would like to see with its own page;
- a request about your personal data, as the privacy notice describes.
One person reads it, in their spare time, so expect an answer within days rather than hours. There is no telephone line; the postal address is in the legal notice.