Is it possible to proxy the auth0 servers during development?

We’re embedding our webapp in a third-party “browser” (basically an embedded webview). However, that webview sandboxes the browser to the same domain as our app – so using our existing Universal Login doesn’t work because the browser won’t open foo.us.auth0.com – it’s locked to foo.com

For production this isn’t a big deal because we can use a custom subdomain of our main site (like login.foo.com) – but it means we can’t auth in development.

Our webapp is running over https with a self-signed cert, would it even be possible to have our backend proxy https://localhost/authenticate -> https://foo.us.auth0.com/authenticate and https://localhost/login -> https://foo.us.auth0.com/login to be able to “serve” the login page from our domain? Is that conceptually possible?