404 error page is not displaying for .php extention file

Hello,

I have a issue in my website.I am using normal php files and wordpress blog inside my website.
the problem is when I go to any page like contact page then it will display as https://www.example.com/contact.php.If I type wrong url like https://www.example.com/contact.php/123f it should diplay the 404 error page,but in my website 404 page is not displaying for .php extension.But 404 page is displaying for all .html extension.

Please help me to clear this issue.

Thanks in advance.