“My API” not sure what you mean by “my API”
This is the wrong URL
Channel Search is at https://api.twitch.tv/helix/search/channels
Documentation: Reference | Twitch Developers
You also omitted an Authorisation token, all of Helix requires an oAuth token to be specified, and you only included a client-id header
If you want to find music streams
You want the music GameID https://api.twitch.tv/helix/games?name=Music which is 26936
And then call get streams with that game_id which is https://api.twitch.tv/helix/streams?game_id=26936
See also Reference | Twitch Developers