Convert Laravel Microsoft Graph example to non-framework

Here is a basic example of how to build a Web app using Microsoft Graph and PHP. But it's in Laravel which I have no knowledge. I need help converting pretty much the same code base into normal PHP that does not require Laravel framework. One difference being no sign-in sign-out feature needed instead application need to get authenticate in the background. I am planning to use it to fetch emails from a mailbox.

docs.microsoft.com/en-us/graph/tutorials/php