How to reference :value from :onchange command.

[LurkAndLoiter]

I'm trying to send an updated value via a scale value on change but i cant figure out how to reference it.

(scale
  :class "media-scroller ${player.CanSeek == false ? "inactive" : "active"}"
  :min 0 
  :max "${round(player.uDuration / 1000000,0)}" 
  :onchange "playerctl --player${player.player} position {}"
  :value "${round(player.uPosition / 1000000,0)}") 

Sorry it's still ugly doing function before form atm.
Ideally I drag the scale bar and send the position update with the dragged position. Actual behavior is the scale will fail to send position update and will be redrawn back into position on next event poll.

[LurkAndLoiter]

Answering myself. {} is the placholder to use. The issue I was having was related to floats. I needed to include :round-digits 0 to make it a whole number.

(scale
  :class "media-scroller ${player.CanSeek == false ? "inactive" : "active"}"
  :round-digits 0
  :min 0 
  :max "${player.uDuration / 1000000}" 
  :onchange "playerctl --player${player.player} position {}"
  :value "${player.uPosition / 1000000}")