When you become a member of OnSong Premium, by subscribing inside of the OnSong app, the subscription payment is processed as an in-app purchase by Apple. However if you've started a free trial, the subscription may not immediately appear in the Manage Subscriptions section of the App Store app. We are not sure why this is the case but it may be a delay in processing on Apple's end.
If you desire to cancel your subscription, the only place to do this is within the App Store since the purchase is made directly with Apple. You should receive an email from Apple before the subscription begins where you can cancel the subscription at that time. Please contact App Store Support if you have concerns as the purchase and subscription is made to your AppleID purchase history and developers do not have access to that information to provide assistance.
If you've subscribed to OnSong through the website using a Solo or Group subscription plan, you will not see any billing information in the App Store app. You can learn how to find your billing history in our support article.