Configuring configuration.yaml for REST API use

Hey guys,
I’m creating an android app based client for my HA server, and I’m willing to use REST API in order to communicate with the server.
Sadly, I couldn’t figure out how I should configure “configuration.yaml” in order to be able to send HTTP Requests to the server.
The documentation says I should add “api:” and “http:” however I couldn’t figure out how I should include them and whether I should or should not include “http:” (which is the ‘api:’ dependency).
can you please upload an example?
I can currently get to my web panel using HA Cloud (Nabu Casa), but when trying to go to /api/ I get 404s instantly.

Thanks in advance y’all