Did I configure app-search.yml right?

I've successfully installed app-search (self-managed) on Ubuntu 18.04. I'm however not sure if I've configured it right. Here are the entries I've modified in my app-search.yml file: -

allow_es_settings_modification: true
app_search.external_url: http://<MY-SERVER-IP>:3002
app_search.listen_host: <MY-SERVER-IP>

I can now access app-search from the http://<MY-SERVER-IP>:3002 and it seems to be working as expected. I'm however wondering if above settings are correct. Should the app_search.listen_host` be set to 127.0.0.1 OR my server IP?

Is there any other setting I should pay attention to when going live with production server? Thank you in advance.

Addendum: Upon restarting the app-search server; I'm unable to load pages. App Search throws -

Completed 401 Unauthorized in 68ms

I'm running with default settings and have not set any credentials to access app-search. What exactly is going wrong?