The 21-day programme is made up of several courses, each guiding you through a series of videos. I can’t recall exactly which lesson covers the question you raised, but it was explained in the material. I’m also not done with the programme and stalled somewhere on the lesson related to finding your own strategies with the studio.
From memory, the process looks something like this:
Choose your platform – MetaTrader 4 or 5.
I prefer MT5, especially if you’re working with EAs. You can download it directly from your broker, or MT5 can be downloaded independently without linking to a broker at first.
Download the EAs suited to the platform you selected (MT5-specific files if you choose MT5).
Install the EAs in MetaTrader:
Open MT5
Go to File → Open Data Folder
Navigate to MQL5 (or MQL4 if using MT4)
Open the Experts/Advisors folder and place your EA files there
Close the window afterwards
Enable live operation for your EAs:
Make sure AutoTrading is turned on in MT5
Go to Tools → Options → Expert Advisors tab
Check Allow Algo Trading
Enable Allow DLL imports and Allow WebRequests
Set up your chart:
In Market Watch, open a chart for the pair the EA is designed for
Select the required timeframe
Ensure Autotrading is enabled
Drag the EA onto the chart
From here, the course lessons go deeper into the different EA types Petko refers to and how to work with them effectively.