JWT structure in PHP

jwt-structure.php

<?php
// JWT structure
// header.payload.signature

// $header
$header = [
    'alg' => 'HS256', // HMAC - SHA256
    'typ' => 'JWT'
];

$headerJson = json_encode($header);
$headerBase64 = base64_encode($headerJson);
echo $headerBase64;
echo "\n\n";

// payload
$payload = [
    'name' => 'Nilton',
    'email' => 'nilton@email.com',
    'exp' => (new \DateTime())->getTimestamp() + 3600
];

$payloadJson = json_encode($payload);
$payloadBase64 = base64_encode($payloadJson);
echo $payloadBase64;
echo "\n\n";

// signature
$key = '76526asdsda125asdasd987asd4';
$signature = hash_hmac('sha256', "$headerBase64.$payloadBase64", $key, true);
$signatureBase64 = base64_encode($signature);
echo "\n\n";
echo $signatureBase64;

?>