How can I load a controller action from loading up a blank URL in Yii2?

I’d like to be able to load up a frontend controller action from a default URL eg. www.mywebsite.com and have it load up the frontend siteController::actionMain().

Is there any changes I can make in my Yii2 project to acheive this?

I tried using a forward in my hosting, however it left me unable to access the backend of my application.