Vanilla PHP JWT Token Generator for Zoom API

jwt.php

$api_key = '[APY KEY]';
$api_secret = '[API SECRET]';
$expiration = time() + 60; //set to 1 minute, for security reasons

$h_array = [
  'alg' => "HS256"
];

$p_array = [
  'aud' => null,
  'iss' => $api_key,
  'exp' => $expiration,
  'iat' => time()
];

$headers = json_encode($h_array);
$payload = json_encode($p_array);

$headers_encoded = base64_encode($headers);
$payload_encoded = base64_encode($payload);

$signature = hash_hmac('sha256',$headers_encoded . "." . $payload_encoded,$api_secret,true);
$signature_encoded = base64_encode($signature);

//build and return the token
$token = $headers_encoded . "." . $payload_encoded . "." . $signature_encoded;