I'm kind of lost ... sorry if the question is stupid but I need help.

My project is this one: https://github.com/miguelsmuller/centro-de-estudos

I set the icons for linux, windows and mac in main.js file. But it happens the following:
In linux: File icon and docker icon is electron standard.
In windows: The file icon is the default of the electron. The icon in docker is the one configured in main.js.

I know I have to configure the electron-builder icon as well. But what the responsibilities of each one. How to configure the icons correctly?