How to create a video for a map?

I have a question: In the videos, in the "sentences" tab, in the second line (after your text), there is something like "sound." That is, a sound that will play throughout the scene as background music. So, if I try to add this sound, in the drop-down list, I don't find any good music (neither battle music, nor game menu music, nor town music), only sounds for various unit actions/mouse clicks, etc. I have configured all of this correctly, just below (next to the effects and animations). How and where can I find good background music?