How to set up Google Pay payment verification on the server?

Question

PHP

Hello!

For implementation, office was used. library:

https://github.com/googleapis/google-api-php-client

$client = new Google_Client();
        $client->setAuthConfig('auth_key.json');
        $client->addScope('www.googleapis.com/auth/a...
        $service = new Google_Service_AndroidPublisher($client);
        $purchase = $service->purchases_subscriptions->get(
            '%packageName%',
            '%productId%',
            '%token%'
        );

Arrives:

{
"error": {
"code": 403,
"message": "The project id used to call the Google Play Developer API has not been linked in the Google Play Developer Console.",
"errors": [
{
" message": "The project id used to call the Google Play Developer API has not been linked in the Google Play Developer Console.",
"domain": "androidpublisher",
"reason": "projectNotLinked"
}
]
}
}

Service account set up to connect with the application.
The rights are maximum.
Maybe there can be a joint in the roles.