Implementing BitPay in YII2

Question

I'm currently implementing BitPay as an additional payment method in our website, using PHP.

I've been following the provided documentation:

https://developer.bitpay.com/reference/php-full-sdk-getting-started#setup

https://developer.bitpay.com/reference/php-full-sdk-create-an-invoice

https://developer.bitpay.com/docs/signed-request-flow

So first I start by creating the private key:

$privateKey = PrivateKey::create(<FILENAME>)->generate();
$storageEngine = new EncryptedFilesystemStorage(<PASS>);
$storageEngine->persist($privateKey);
$privateKey = $storageEngine->load(<FILENAME>);

$publicKey = $privateKey->getPublicKey();

As I understood the SIN is the hash of the public key:

$sin = $publicKey->getSin()->__toString();

We'll be using the PoS facade, which should be sufficient for basic invoice creation, according to their documentation:

$resourceUrl = 'https://test.bitpay.com/tokens';

$facade = 'pos';

$postData = json_encode([
    'id'     => $sin,
    'label'  => 'Token',
    'facade' => $facade
]);

$curlCli = curl_init($resourceUrl);

curl_setopt($curlCli, CURLOPT_HTTPHEADER, [
    'x-accept-version: 2.0.0',
    'Content-Type: application/json',
    'x-identity' => $publicKey->__toString(),
    'x-signature' => $privateKey->sign($resourceUrl . $postData),
]);

curl_setopt($curlCli, CURLOPT_CUSTOMREQUEST, 'POST');
curl_setopt($curlCli, CURLOPT_POSTFIELDS, stripslashes($postData));
curl_setopt($curlCli, CURLOPT_RETURNTRANSFER, true);

$result = curl_exec($curlCli);
$resultData = json_decode($result, TRUE);
curl_close($curlCli);

$token = $resultData['data'][0]['token'];

$bitpay = new PosClient($token, 'test');

$invoice = new Invoice(<AMOUNT>, Currency::USD);
$invoice->setToken($token);
$invoice->setToken($token);
$invoice->setFullNotifications(true);
$invoice->setExtendedNotifications(true);

$client = new Buyer();
$client->setName(<NAME>);
$client->setEmail(<MAIL>);
$client->setAddress1(<ADDRESS>);
$client->setCountry(<COUNTRY>);
$client->setLocality(<CITY>);
$client->setNotify(true);
$invoice->setBuyer($client);

try {
    $new_invoice = $bitpay->createInvoice($invoice, Facade::POS, false);

} catch (\Exception $e) {
    print_r($e->getMessage());
}

The private key is created and the call to their API is successful. The response is the same as expected and the token is obtained:

{"data": 
 [{"policies": 
 [{"policy":"id", 
 "method":"inactive", 
 "params":["Tf3wXWuwfT1TmenHF21P1nYZ7BeyrYNdiwo"] 
 }], 
 "token":"<TOKEN>, 
 "facade":"pos", 
 "label":"Token", 
 "dateCreated":1696926578101, 
 "pairingExpiration":1697012978101, 
 "pairingCode":"<CODE>" 
 }] 
}

However the problem that I'm experiencing, is that when I try to create the invoice in the final step, I'm hitting the below exception:

"BITPAY-INVOICE-CREATE: Failed to create invoice-> failed to serialize Invoice object : failed to retrieve HTTP response body : Token is disabled"

It's either that, or I get Token is invalid. Is there something that I'm missing?

Tried using the merchant/payout instead of POS as well, using the create with file option:

Client::createWithFile();

The result is the same. The .env file is the json template mentioned here: https://developer.bitpay.com/docs/signed-request-flow#overview