Info about Expert Advisor based on Custom Indicator or Existing MT4 indicators

 

Hi, i'm learning MQL in my free time, and I'm currently trying to learn one basic thing but Can't find info about this or documentation.

Let say i'm trying to code an Expert Advisor to open orders based on the output of indicators on the charts, for example when the William's Fractals open the Arrow Up i want to open a Buy.

Any idea, links, or documentation on how to do this?

Also my idea is to build an expert advisor based on a few indicators that I have, will this be any different than the example above?

Please help me out because i don't know where I can find info about this.

 
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