How to attach events to AAMP Player?

I have this(above image) player page code which plays Dash streams using AAMP Player, I want to attach events to aamp player(following this document) so that i can add loader and some placeholder image as the background while the stream loads and hide it when video starts playing and vice versa. I added as mentioned in the above document
this.player.addEventListener('playbackStarted', (e) => { this.tag('Background').alpha = 0; this.tag('Title').alpha = 0})
to hide the backgorund and title and show the stream but this event listener is not working, did anybody else faced this issue, if so how to resolve this? Please help.