How to make a link click open a native SMS message on android or ios

sms_msg_link.php

<?php

//uses https://packagist.org/packages/mobiledetect/mobiledetectlib

$body = "Hey this is a new sms message";
$url = "http://example.com/path/to/fallback/url";

$detect = new MobileDetect();

if ($detect->isMobile()) {

    if ($detect->isIphone()) {
        $url = "sms:" . $phone . "&body=" . rawurlencode($body);
    }

    if ($detect->isAndroidOS()) {

        $url = "sms://" . $phone . "?body=" . rawurlencode($body);

    }

}//end if

header("Location: {$url}");