Hello
I put a condition ( the music file on a channel played ) and events for it, but it doesn’t work.
How can i do that? I mean that i want events to be active when a music is finished.
Hello, kattan 
There is a advice in the wiki:
“Before a sound/music can be played, you have to first ensure that the player interacted with your game (a simple click/touch on the screen is ok to unlock audio). This is a limitation of browsers and cannot be worked around. In your final game, it’s recommended to have on your first scene a “Press any key or touch the screen to continue” message.”
Your music file is mp3, wav, ogg or AAC?
Try to change your music event to a sound event, because the music events are an older method.