I think everybody knows about it that there are different volume control for music and sounds in games respectively. Do we have same feature in GDevelop? If yes then. What is the way to do so?
Simply play the music and the sound effects separately on different channels. Then change the volume of those channels. Each channel has several attributes that can be changed and affect all the sounds/music currently playing on that channel (such as pitch and volume). You can also stop the sounds/music on individual channels.
To change the volume:
In actions: Audio>Music on channels>Volume of the music on a channel
In actions: Audio>Sounds on channels>Volume of the sound on a channel
Music is best used for files with longer duration, sound is better for short duration.
I though that too, but the problem is I don’t know how to create a channel for music or sound? 
Can you tell me how to do so? Please!