When we have to configure a multi-store in your local machine you can configure the local NGINX or Apache configuration to make it work, or you can quickly change your index.php just to test, fix the issues and not commit this change.

In this same case just to test using Magento 1 we used to change the $mageRunCode and $mageRunType in the .htaccess or httpd.conf.

In Magento 2 to test quickly you can use that code into your index.php:

$params = $_SERVER;
$params[\Magento\Store\Model\StoreManager::PARAM_RUN_CODE] = 'website_code';
$params[\Magento\Store\Model\StoreManager::PARAM_RUN_TYPE] = 'website';
$bootstrap = \Magento\Framework\App\Bootstrap::create(BP, $params);