How can i make other audio/song be played when one of them stops javascript?

I´m new to html js and css and my objective is do anything similar to spotify or any app that plays music and my objective is other audio plays when one of them stops. I tried this, but it doesnt work when i load the page the audio is already on 10 seconds stated on the "if" and the alert pops up... probably this is very easy but, you know just learning.

 if (audio.currentTime = 10) {
    
  alert("Hello! I am an alert box!!");
    
    }