Help plotting Channel

I am sure it is something simple I am missing, but I am trying to port over a channel indicator from TradingView, but I am not getting anything to plot on the chart.

My indicator is shared and the name is “Murrey Math Lines” and below is what I am trying to imitate from TradingView:
// plot midline from Murrey Math for trifecta entry and exit
// Inputs
length = input(100, minval = 10, title = “Murrey: Look back Length”)
showmidline = input(true, title = “Murrey: plot midline”)

// begin MMM line
hi = highest(high, length)
lo = lowest(low, length)
range = hi - lo
midline = lo + range / 2

plotmidline = showmidline == true ? midline : na
plotrange = lo

plot(plotmidline, title=“Murrey Math Midline”,color=white)
plot(plotrange, title=“Murrey Math Range low”,color=fuchsia)
plot(plotrange + range, title=“Murrey Math Range high”,color=fuchsia)

Any suggestions?