jwt-gen

#!/usr/bin/env php
<?php

function base64UrlEncode($text)
{
    return str_replace(
        ['+', '/', '='],
        ['-', '_', ''],
        base64_encode($text)
    );
}

// Create the token header
$header = json_encode([
    'alg' => 'HS256',
    'typ' => 'JWT',
]);

// Create the token payload
$payload = json_encode([
    'device_id' => $argv[1],
]);

// get the local secret key
$secret = $argv[2];

// Encode Header
$base64UrlHeader = base64UrlEncode($header);

// Encode Payload
$base64UrlPayload = base64UrlEncode($payload);

// Create Signature Hash
$signature = hash_hmac('sha256', $base64UrlHeader.'.'.$base64UrlPayload, $secret, true);

// Encode Signature to Base64Url String
$base64UrlSignature = base64UrlEncode($signature);

// Create JWT
$jwt = $base64UrlHeader.'.'.$base64UrlPayload.'.'.$base64UrlSignature;

echo "Your token:\n".$jwt."\n";

1- put inside root project directory
2- chmod +x jwt-gen
3- ./jwt-gen <device_id> <secret>