title: how i can add alert and plot for this strategy?
body: <p>Code:</p>
  <pre><code>//@version=5
  strategy(&quot;BTCTEST&quot;, overlay=true)
  len = input(7)
  nATRs = input(0.4)
  atr = ta.sma(ta.tr, len)*nATRs
  
  if (not na(close[len]))
      strategy.entry(&quot;Long&quot;, strategy.long, stop=close+atr, comment = &quot;Long&quot;)
      strategy.entry(&quot;Short&quot;, strategy.short, stop=close-atr, comment = &quot;Short&quot;)
  </code></pre>
  <p>This is my modify</p>
  <pre><code>//@version=5
  indicator(&quot;BTCTEST&quot;, overlay=true)
  len = input(7)
  nATRs = input(0.4)
  atr = ta.sma(ta.tr, len)*nATRs
          
  //if (not na(close[len]))
    //strategy.entry(&quot;Long&quot;, strategy.long, stop=close+atr, comment = &quot;Long&quot;)
    //strategy.entry(&quot;Short&quot;, strategy.short, stop=close-atr, comment = &quot;Short&quot;)
  
  ebuy = ???
  esell = ???
      
  plotshape(ebuy,  title = &quot;Buy&quot;,  text = 'Buy',  style = shape.labelup,   location = location.belowbar, color= color.green, textcolor = color.white, transp = 0, size = size.tiny)
  plotshape(esell, title = &quot;Sell&quot;, text = 'Sell', style = shape.labeldown, location = location.abovebar, color= color.red,   textcolor = color.white, transp = 0, size = size.tiny)   
          
  alertcondition(ebuy, title='BUY', message='e=bitmex s=xbtusd delay=1 b=buy t=market q=100% d=1')
  alertcondition(esell, title='SELL', message='e=bitmex s=xbtusd delay=1 b=sell t=market q=100% d=1')
  </code></pre>
  <p>i don't understand <code>stop=close+atr</code> and <code>stop=close-atr</code> , <code>if (not na(close[len]))</code></p>
  <p>How should I check long and short? I spent many hours for this. I hope someone can help me.</p>