How to change current time of sound when this is playing

[chipnin]

Now i'm buiding a player music.
I created play with: play, pause, resume, and created process bar when playing.

But I have a problem, i want to change current time of music when it's playing. but i can't not change it.

i using code, but currrentTime not change when sound is playing.
 

// in create function:
music = this.add.audio('audio-song'); 
music.play();

// when click pointer in process bar
music.currentTime = 20000; // 20s after