1. Open the Play Store on your Android device.
2. Tap your profile icon at the top right corner.
3. Tap Payments & subscriptions.
4. Tap Subscriptions.
5. Select the DPM subscription.
6. Tap Cancel subscription.
More information can be found in this article: https://support.google.com/googleplay/answer/7018481
Please note that your subscription is not canceled automatically after you uninstall the app.