Automating Plexamp on iPhone

I have a spare iPhone which I am using as a music player (using the Plexamp app). The iPhone is integrated to Home Assistant.

I am battling to create an automation to play and pause the music.

For example, to pause the music, under Actions I have selected Media Player: Pause as a service, and then added the Plex media player as the entity. Nothing happens when I select Run.

This is what I have:

alias: Pause Plexamp
description: “”
trigger: []
condition: []
action:

  • service: media_player.media_pause
    data: {}
    target:
    entity_id: media_player.plex_margar826_plexamp_nevilles_iphone
    mode: single

What am I missing?