PayPal\Handler\OauthHandler::_getEndpoint PHP Method

    private static function _getEndpoint($config)
    {
        if (isset($config['oauth.EndPoint'])) {
            $baseEndpoint = $config['oauth.EndPoint'];
        } elseif (isset($config['service.EndPoint'])) {
            $baseEndpoint = $config['service.EndPoint'];
        } elseif (isset($config['mode'])) {
            switch (strtoupper($config['mode'])) {
                case 'SANDBOX':
                    $baseEndpoint = PayPalConstants::REST_SANDBOX_ENDPOINT;
                    break;
                case 'LIVE':
                    $baseEndpoint = PayPalConstants::REST_LIVE_ENDPOINT;
                    break;
                default:
                    throw new PayPalConfigurationException('The mode config parameter must be set to either sandbox/live');
            }
        } else {
            // Defaulting to Sandbox
            $baseEndpoint = PayPalConstants::REST_SANDBOX_ENDPOINT;
        }
        $baseEndpoint = rtrim(trim($baseEndpoint), '/') . "/v1/oauth2/token";
        return $baseEndpoint;
    }