Create multiple header in php

You could use cURL for this: http://php.net/manual/en/book.curl.php

Essentially cURL allows you to contact URLs "behind the scenes" (rather than using an HTTP Redirect) - but there are several settings that will depend on your setup... and there are a lot of cURL settings: http://php.net/manual/en/curl.constants.php

However, in essence here you'll want a function which just contacts the given URL - maybe throws an Exception if the URL can't be reached.

function curlCreatePDF($sURL) {

    //open the cURL session
    $hCurl = curl_init();

    //set the cURL options
    curl_setopt($hCurl, CURLOPT_URL, $sURL); //URL
    curl_setopt($hCurl, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_1_1); //HTTP version
    curl_setopt($hCurl, CURLOPT_HEADER, 0); //no HTTP headers
    curl_setopt($hCurl, CURLOPT_RETURNTRANSFER, 1); //return raw data to script rather than browser
    curl_setopt($hCurl, CURLOPT_TIMEOUT, 60); //set timeout

    //execute
    curl_exec($hCurl); //this will actually return the response

    //throw an Exception if cURL failed
    if($e = curl_error($hCurl)) {
        throw new Execption($e, E_USER_ERROR);
    }

    //close the cURL handle
    curl_close($hCurl);
}

// I need to create 2 different pdf , (pdf is created when we go to create_Pdf.php)
try {
    for($i=0;$i<2;$i++) {
        curlCreatePDF("http://www.yoursite.com/path/to/Create_PDF.php?idcode={$code}&inputdate={$datein}&outputdate={$dateoutfr}&username={$usernameOut}");
        curlCreatePDF("http://www.yoursite.com/path/to/Create_PDF.php?idcode={$code}&inputdate={$datenominate}&outputdate=31/12/2015&username={$usernameIn}");
    }
}
catch(Exception $e) {
    die($e->getMessage());
}

This may not work "as is", especially over SSL (as you'll need to set the CURLOPT_SSL_VERIFYPEER and CURLOPT_SSL_VERIFYHOST options)...

It would make more sense though to just put your create PDF stuff into a class and then just call it in your loop rather than calling an external file over HTTP.