Webostv.command 'tv/getChannelProgramInfo'

I would like to show the “Channel Program Info” from my LG TV on a picture-elements card.
I’m trying to use “tv/getChannelProgramInfo” (see) but I can’t figure out how to use this command.
I’ve made a picture-elements card by which I can select sound output, volume, sources and TV channels. It also shows the state of the selected items (the list on the top left side). For this list I’m using the attributes of the entity ‘media_player.tv_woonkamer’:

Everything works fine except for the “Info:”
At the moment it returns the state of the media_player (media_player.tv_woonkamer).
I’ve made this element for “Info”:

    - type: state-label
      entity: media_player.tv_woonkamer
      command: 'webostv.tv/getChannelProgramInfo'
      prefix: 'Info: '
        transform: none
        top: 40%
        left: 5%

Unfortunately this doesn’t do the job.
I’ve also tried it with a sensor:

 - platform: template
       value_template: >
         {% set info = state_attr('media_player.tv_woonkamer', 'tv/getChannelProgramInfo') %}
         {% if (states('media_player.tv_woonkamer')) == 'off' %}
         {% set info = '' %}
         {% endif %}
         {{ info }}

I know that ‘tv/getChannelProgramInfo’ is not a attribute of ‘media_player.tv_woonkamer’.
I probably have to use the service ‘webostv.command’. But I don’t know how to get this done.
Can anyone help to solve this problem?
Because it would be great to show the program info on my picture card and (not in the least) I would like to learn more about how to get this kind of things done in Home Assistant.