Zendesk\API\Utilities\Auth::prepareRequest PHP Метод

    public function prepareRequest(RequestInterface $request, array $requestOptions = [])
    {
        if ($this->authStrategy === self::BASIC) {
            $requestOptions = array_merge($requestOptions, ['auth' => [$this->authOptions['username'] . '/token', $this->authOptions['token'], 'basic']]);
        } elseif ($this->authStrategy === self::OAUTH) {
            $oAuthToken = $this->authOptions['token'];
            $request = $request->withAddedHeader('Authorization', ' Bearer ' . $oAuthToken);
        } else {
            throw new AuthException('Please set authentication to send requests.');
        }
        return [$request, $requestOptions];
    }