Using own image for interactive avatar icon

Hey there, I'm having an issue replacing the avatar icon with my own image. The image is set to display in front of the iframe content so its blocking the button click. I'm not able to click on the "chat now" and nothing happens when I click on the image.

Is there some kind of auto chat start parameter? Like '&autostart=true'? That way I'd be able to embed the iframe in a WP popup instead.

Thanks,

Karolina