Paragraph username and password works fine with a simple html form.
But when someone does not have valid user name and password, I had the idea to
create a link that takes you to a pre-registration form which asks for
your full
name, school data, and they put your username and password sua to start
authentication. this is where I got the idea that using a php script
catching your data and send them to me by email, and since the server side
with captive portal, giving them high in the section of users already can
authenticate

The form runs fine but when you invoke the PHP script that no longer worked
for me only displays all the code of PHP script like a simple text file. this
is where I did not know what to do.

Yours sincerely