There is no "protected" folder

According to the twitter extension there should be a “protected/config/main.php”
I have installed using composer the basic application and the advanced application. Neither includes the main.php file. I don’t want to create it because it requires a JSON structure that should contain a components section where I can add the “twitter” section of it. So where should I get this main.php file in order to continue installation.

That extension is for Yii 1.1.
(Yii 2 extensions exists e.g. yii2-social).