It should be in your mail, try searching for a message from the platform you are playing on. If it’s not there, try this to find your transaction ID.
Google play:
.If nothing comes up, try this:
You can get a receipt online:
1. Visit Google Pay.
2. Sign in to your Google account.
3. Click Activity.
4. To get your receipt, select an order.
App Store:
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.
5. Your purchase history appears.