@aqeeliqbal I never heard a product that can do that. if you on the true silent mode you won’t hear anything on youtube. it just doesn’t make sense.
But it can be you are a bit confused about silent your incoming calls/message alerts then silenting your device volumes. these are two different mecansims and as long as you are on call/messages silent you cocos2dx games will still be capable of playing music.
However when the device volume is shutdown completely there is no way you can make the game make any sound and honetly if this is a requirement you have, you should change your design