The Problem

I'm dipping my toes into AWS by deploying a simple API built with NestJS. This will be the first app I've deployed to a cloud service. I've already cloned my repository on an AWS Lightsail Linux instance with Node.js and installed all of my dependencies. However, I'm confused on how best to provide environment variables to my app.

Obviously, I has a local .env file that I used during development with credentials for my database, port info, etc. Do I just create a new .env file on the machine running my instance through the command line? I've read that for other AWS services you can provide env variables through that service's UI, but I can't find the same thing for Lightsail.

I would greatly appreciate it if someone could give me an explanation of env variables, and how we should generally provide them to cloud services.

Thank you!