We don’t manage your subscription, the store does. If you’re using the Windows app, it’s managed by Microsoft, if you’re using the Android version, it’s managed by Google.
If it’s Windows app, please follow these steps : https://support.microsoft.com/en-us/account-billing/how-to-cancel-your-microsoft-subscription-c2c6b0e3-cab3-cb98-d83e-c9ad54620530
If it’s Android, please read the guides here: https://support.google.com/googleplay/answer/2479637?hl=en