In case of a payment problems, make sure that ...
1. you have a stable internet connection when you try to subscribe to the Coach.
2. you have set up a working payment method in the Apple App Store or Google Play Store.
If that does not help, please try the following:
1. Close the app, restart it and initiate another payment process.
2. Restart your phone and initiate another payment process.
3. Uninstall and reinstall the app and initiate another payment process.
Unfortunately we have no influence on the payment systems of Apple and Google. If the problem persists, please contact the App Store or Google Play Store Customer Support.