When creating a new class, a new include file template for describing that class is created. This file automatically placed in an MQL5/Include (or MQL4/Include) directory. When creating a class, you can indicate a base class for it. This will be considered in the template as well.
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 in this window:
Depending on the conditions of calling the MQL4/MQL5 Wizard a corresponding path is substituted in the "Include file" field:
Once all the necessary fields are filled out, the "Done" button will become active. As soon as it is pressed, the project of the class file will be created and the window for writing its source code will be opened automatically.