How do I create a lockdown exception for a site I can't browse to?

Is there a way to exclude a site from lockdown mode that doesn't require me to browse to the site first?

I have the Target app excluded from lockdown mode. But when I tap the app's "show my barcode" button a series of web pages flashes by briefly. One of them, gsp.target.com, still says "lockdown enabled". I tried to browse to that site so I could mark it as excluded, but the site only offers me a file to download, and doesn't show the URL in a browser so I can't set the "exclude" switch.

Whatever that site is supposed to do is being blocked, so the app never shows my barcode.