REST intergation

is there more documentation about using the rest api with metforms?
any example code?

i try to use the rest api integration to add some rules for sending an email with the form data but somehow my code seems to do nothing. when i test it with postman it seems to work just fine.

<?php

header(“Access-Control-Allow-Origin: *”);
header(“Content-Type: application/json; charset=UTF-8”);

$text = “”;

foreach($_REQUEST as $key => $value) {
if($value != “”) {
$mailArr[$key] = $value;
$text = $text . $key . “: ” .$value . “\n”;
}
}

//apply the rules

//send mail
$empfaenger = “[email protected]”;
$betreff = “Die Mail-Funktion”;
$from = “From: Vorname Nachname <[email protected]>”;

mail($empfaenger, $betreff, $text, $from);

$json_response = json_encode($mailArr);
echo $json_response;
?>