I can´t run .php pages on my Microsoft Azure Web Aplication

I'm trying to hoost a website on Microsoft Azure and I did it. But when I enter in my website to a .php page the browser answer with the next error message: "The page cannot be displayed because an internal server error has occurred."

Before that, it returned a 500 error code, but searching the internet I tried to configure de Handler Mappings option (I dont know if I did it good or not, but now that is the new error message).

Is there any required configuration I have to do in order to make .php pages work? I have the "shared" payment plan, Do I need a better payment plan in other to do it?

Thank you!