Redirect a virtual url

Question

How do I redirect a url from my website to a subfolder.

Example:

Database:

ID | ENDEREÇO | ESCREVER NO INDEX.PHP 1 | example.com/extranet | <span>Sou o extranet</span> 2 | example.com/topico1 | <span>Sou o topico1</span>

In case what I want is for the user to access the URL without having to create several folders on the server with an index in them. thus making navigation simpler.

I thought about an array, but I don’t know how it works much this redirecting.

NOTE: This is a Technica if I’m not mistaken 000webhost.com uses in Zyrowebsitebuilder.

An array for example:

$pages = array(
        '0' => array('id' => '1', 'alias' => 'extranet', 'file' => '1.php'),
        '1' => array('id' => '2', 'alias' => 'topico1', 'file' => '2.php'),
        '2' => array('id' => '3', 'alias' => 'topico2', 'file' => '3.php')
    );

And in the case after that array it executes include('$pages[NUMERO]');