We use all kinds of apps on our phones for different functionality. By default, this cannot be reflected in Android app volume settings. Adjustment although. You might want Spotify to turn on at full power every time you open it, but you want to suppress annoying in-game sound when you open it on the bus.
If you want more control over the volume on a per-app basis, App Volume Control For you. This app allows you to set specific volume levels within each of your android apps. On the first launch, you will need to enable the accessibility service, through which the application will help you.

By default, the app will show you everything installed on your phone, including system apps. You probably won’t need to change them, so to reduce the clutter you can hit the settings button and disable Show system apps, to see only your installed applications.
You can also turn off the notification while you’re here. that the app shows every time it performs a volume change, which is annoying.
Select any app to change its volume into five categories: media (app sounds like in-game music), ring (your phone’s ringtone), alarm clock (your phone’s alarm function), notification (other apps send you notifications), as well as systems (telephone noises from pressing the keyboard, etc.).