Change src dynamically

[Ederish_Herrera]

suppose an audio

this.load.audio('song1','assets/audio/level-1.mp3');

and convert the url to a variable

this.load.image('img1', songURL);

var songURL = 'assets/img/lofi-1.jpg';

How do I change the value of the variable when I click on one of the boxes?
I tried with:

r1.on('pointerdown', () => songURL ="'assets/audio/level-1.mp3'" )

and with :

r1.on('pointerdown', () => songURL.src ="'assets/audio/level-1.mp3'" )