access environment variable in React-Native AndroidManifest.xml

I'm new to React Native. The task at hand is to set my Google API key in AndroidManifest.xml without exposing it, when pushed to GitHub. I set up an environment variable called API_KEY, but however I want to access it in the .xml, I get an error when trying to spin up the dev server.

So far I tried:

android:value=${env.API_KEY}
android:value="${env.API_KEY}"
android:value="${API_KEY}"

Thank you!