Simple Loading Bar using SceneManager.LoadSceneAsync

Hi guys, I wonder if you could please help me?

I would like to create a Loading Screen with a simple Loading Bar. The idea is that obviously once a player clicks on the “Start Game” button, the Loading Screen displays (with the loading bar), loads everything asynchronously and the game begins.

I have tried searching the forums for a conclusive method/script as to how to do this using SceneManager.LoadSceneAsync.

I am not fussy as to whether the loading bar itself is actually slider or image with fill effect.

Could somebody please provide me with a basic script on how to do this?

http://lmgtfy.com/?q=unity+loading+bar

Seems to be a lot of results when googling for it…