How to change the media player background picture

Configuration Frontend
1

Hi there.

I have 2 LG tvs, and they are both webos. I successfully added them to my HA. Most of the time, I use source “HDMI2” (my cable tv);;
and there is no background picture. when I watch Netflix, amazon video, the background changes automatically,

Is there any way to set a picture when the source is HDMI2?
configuration.yaml:

webostv:
  - name: TV sala
    host: 192.168.0.66
    turn_on_action:
     service: wake_on_lan.send_magic_packet
     data:
      mac: "18:c9:11:18:cb:xx"

HDMI2, with no pic
hdmi2
when watching Netflix and amazon video.
amazon netflix

thank you very much.