Hi,
I supposes that this restaurantdirect.ca/register URL is a menu item of the type Joomla user registration.
The purpose of the redirect plugin is to redirect from the Joomla user registration form to the HikaShop user registration form.
That way, even if the URL is generated by a third party module, or someone somehow try to access it directly, he will have to go through HikaShop's registration form.
The advantage of that is that you then force the customer to provide his address, and you can also have a faster registration since HikaShop has options to remove the password, the username and the name fields form its registration form.
However, with the Joomla SEF URL routing system a page can only display properly if the current menu item is of the same component as the main content.
So if you try for example to display the HikaShop registration form on a page where the current menu item is a Joomla registration form, it will likely result in a 404 error.
To avoid that, the redirect plugin has a parameter when you can specify the id of a HikaShop menu item and it will then use that menu item.
By default that setting is empty, and in that case, the plugin will automatically look for a HikaShop menu item to use for the redirection.
In your case, it seems that the plugin automatically selected cities/calgary menu item.
If you don't want that, just enter the id of a HikaShop menu item in the setting of the redirect plugin. But note that you shouldn't enter the id of the "register" menu item since it's not a HikaShop menu item. If you want to use the URL restaurantdirect.ca/register for your registration page, you can. But in that case, you need to change its type to a HikaShop user registration form page. And if you do, whether you activate this redirect plugin or not, the "register" menu item will have the same URL and display the same thing.
However, with the plugin activated, the link to the Joomla registration form on the Joomla login module will point to that URL instead of a Joomla user registration form, so it's still interesting to have it activated to have a consistant registration form on all your website.