EMA/WMA crossover

 

Folks, I am trying to make an alarm alert for when a EMA of say 25 crosses over WMA of 160 on a 3 minute chart. The alert would sound 20 seconds before the 3 minutes is finished (if that makes sense) could someone please help me code this.

Thanks in advance for your help

J

 
3 minute chart, "yes we can" LOL
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