CSRF problem in development with 'Discourse OpenID Connect' plug-in

I’m not recommending it, but for local development I took the somewhat brutal approach of editing the plugin’s callback_url method: discourse-openid-connect/lib/omniauth_open_id_connect.rb at main · discourse/discourse-openid-connect · GitHub.

     def callback_url
        full_host = 'http://localhost:4200'
        full_host + script_name + callback_path
      end

That way it always returns http://localhost:4200/auth/oidc/callback

Without that change, I couldn’t find a way to get the host part of the URL set to anything other than http://127.0.0.1:3000