Specify different `authServerUrl` for server vs. browser.

I'm using the keycloak-connect middleware for node.js, and I have an issue with the authServerUrl config option.

For the node app where the middleware is applied, the keycloak server will be reachable by some private URL which is not reachable over the internet.

For the browser application which will be redirected to the keycloak login page, the keycloak server will be reachable by a public URL, which is not reachable from inside the private network.

It would be technically possible for me to change how my network is setup so that both the frontend and backend can reach the keycloak server from an identical URL, but I don't want to have to do this.

It would be great if I could specify two different urls for reaching the keycloak server: one for my server-side app to talk to, and one for the browser-side app to be redirected to. Is this possible?