An Expert Advisor template is a file designed for writing a source code. After it has been created, it is automatically placed in an MQL5/Scripts (or MQL4/Scripts) directory.
After choosing the corresponding position in the MQL4/MQL5 Wizard and pressing the "Next" button the following window appears:
The following fields should be filled out in this window:
Variables of the "input" class refer to external parameters. In order to create a parameter one should press the "Add" button. There are three fields that should be filled out in the appeared entry:
Once all the necessary fields are filled out, the "Done" button will become active. As soon as it is pressed, the project of the script will be created and the window for writing its source code will be opened automatically.