How to make it so that only the sound from one app on iPhone bluetooth speakers?

I have bluetooth speakers connected to my iphone when I'm at home and when I'm listening to music on spotify and playing a game at the same time. Sometimes depending on what game it is the game will pause spotify and only play the game sound. Even if I turn the game sound off in the game settings. I've looked everywhere in the iPhone settings and I can't find anything. It isn't just when I'm using my bluetooth speakers but I'm wondering if there's a way in which I can set spotify to play through the speakers and the game sound through my phone or to just turn the game sound off altogether without if interrupting my spotify everyone I open an app

Sorry buddy no idea!