Инструкция по созданию JWT

if(!class_exists('JWT')){
class JWT
{
function __construct(){

} 

function encode($payload, $key)
{
$algo = 'RS256';
$header = array('typ' => 'JWT', 'alg' => $algo);

$segments = array();
$segments[] = $this->urlsafeB64Encode($this->jsonEncode($header));
$segments[] = $this->urlsafeB64Encode($this->jsonEncode($payload));
$signing_input = implode('.', $segments);

$signature = $this->sign($signing_input, $key);
$segments[] = $this->urlsafeB64Encode($signature);

return implode('.', $segments);
}

function sign($payload, $key)
{
$passphrase = '';

$algo = OPENSSL_ALGO_SHA256;
$key_type = OPENSSL_KEYTYPE_RSA;

$privateKey = openssl_pkey_get_private($key, $passphrase);

if (is_bool($privateKey)) {
$error = openssl_error_string();
throw new Exception($error);
}

$details = openssl_pkey_get_details($privateKey);

if (!array_key_exists('key', $details) || $details['type'] !== $key_type) {
throw new Exception("Invalid key provided");
}

$signature = '';

if (!openssl_sign($payload, $signature, $privateKey, $algo)) {
$error = openssl_error_string();
throw new Exception($error);
}

return $signature;
}

function jsonDecode($input)
{
$obj = json_decode($input);
if (function_exists('json_last_error') && $errno = json_last_error()) {
$this->_handleJsonError($errno);
} else if ($obj === null && $input !== 'null') {
throw new Exception('Null result with non-null input');
}
return $obj;
}

function jsonEncode($input)
{
$json = json_encode($input);
if (function_exists('json_last_error') && $errno = json_last_error()) {
$this->_handleJsonError($errno);
} else if ($json === 'null' && $input !== null) {
throw new Exception('Null result with non-null input');
}
return $json;
}

function urlsafeB64Decode($input)
{
$remainder = strlen($input) % 4;
if ($remainder) {
$padlen = 4 - $remainder;
$input .= str_repeat('=', $padlen);
}
return base64_decode(strtr($input, '-_', '+/'));
}

function urlsafeB64Encode($input)
{
return str_replace('=', '', strtr(base64_encode($input), '+/', '-_'));
}

function _handleJsonError($errno)
{
$messages = array(
JSON_ERROR_DEPTH => 'Maximum stack depth exceeded',
JSON_ERROR_CTRL_CHAR => 'Unexpected control character found',
JSON_ERROR_SYNTAX => 'Syntax error, malformed JSON'
);
throw new Exception(
isset($messages[$errno])
? $messages[$errno]
: 'Unknown JSON error: ' . $errno
);
}
}
}

$private_key = "{здесь Ваш privateKey}";
$uid= "{Здесь Ваш uid}";
$request = array('exp' => time() + 3600, 'jti' => bin2hex(random_bytes(12)));
$class = new JWT();
$payload = $class->encode($request, base64_decode($private_key, true));
$post_data = array('kid' => $uid, 'jwt_token' => $payload);

print_r($post_data);
?>