title: Environment Variables for static site?
body: <p>I'm considering deploying a React app as a static site, to cloud storage bucket.</p>
  <p>There're some api keys are needed for the app but I could not find a way to set environment variables in cloud storage.</p>
  <p>Is it even possible to use environment variables in cloud storage?</p>
  <p>GCP Secret Manager may be an option, but looks like it's for server side. And it requires auth but my main purpose of using environment variables is to store Firebase keys used in firebase authentication.</p>
  <p>Any suggestions?</p>