Purchase history can be found in the settings of each platform:

iOS 

1.      Open the Settings app.

2.      Tap your name, then tap Media & Purchases.

3.      Tap View Account. You might be asked to sign in.

4.      Tap Purchase History.

Android

1.      On your mobile device, open the Play Store.

2.      At the top right, tap your profile icon.

3.      Tap Payments & subscriptions Budget & history.