What would be the solution to move a vanilla PHP code to an AWS serverless environment?

[Midas-TusharS]

There are lots of applications that are developed without any framework, Such applications contain business logic and view part on same page, which means PHP, HTML, JS, and CSS on the same page to server users request.

I have an application that is quite big in nature and has two types of code, vanilla php-based code and framework-based code.
Refactoring existing vanilla PHP-based code is not an option for us.

What would be the solution to move a vanilla PHP code to an AWS serverless environment?