Relax Yoga Music offers 2 ways to access paid content: subscriptions and individual packages (sounds, brainwaves, meditations, courses, Music Player). Packages can be restored from the app Settings, whereas subscriptions are automatically restored. Go to this page to know more about subscription restoration.
First, you'll need to make sure to log in to the same Apple ID as the one you used to purchase packages. Then, go to Menu, tap Settings and tap Restore purchases. Type your password, and the app will make sure to restore your past purchases. You can restore them on any iOS device that uses the same Apple ID with the same app.
If you need help, reach out to firstname.lastname@example.org!