Using website accessibility checker after converting PHP file to HTML does not work

I have some PHP files, my IT department wants to perform accessibility checks on these files, but they said that these files need to be converted to HTML first before they run the checker on them.
Now, I loaded the pages in browser and save them as HTML, but what happens is that the accessibility checker extension which is installed on chrome, does not work anymore. It only works on the PHP files that I see in my browser. Has anyone had a similar experience? Is there any way to fix it?