Using third party REST API, how to?

I am working on a project that involves connecting to a third party REST API.

I'm struggling to find a way to connect, as the few CI libraries I have found are either too old, have no proper documentation, are in French, or a mix of all the above!

I need to be able to set the URL endpoint, set a few headers (the REST API expects two API keys with specific names) and at times, request content (e.g. for POST calls)

What are my options in terms of a CI library?

I have tried the following, with zero luck (typically the documentation just doesn't explain much/the code is old and abandoned or deprecated)

https://github.com/philsturgeon/codeigniter-restclient
https://github.com/maltyxx/restclient