Got from https://mylittlepony.hasbro.com/en-us/media/my-little-pony-friendship-quests-game:F4BF82B9-4D3C-4419-8477-A8B605B49AC9

I am not sure whether this is a bgm piece or a song instrumental, but i think it's the former. I haven't heard this before(as i don't listen to bgm often), it might as well belong to a future episode!