CODE EXAMPLE FOR SHELL

store environment variables in firebase functions

$ cd project_directory
$ cd functions
$ firebase functions:config:set api_key1="YOUR_API_KEY1" api_key2="YOUR_API_KEY2"

// Accessing the Keys in Code

const functions = require('firebase-functions');

const api_key1  = functions.config().api_key1;
const api_key2  = functions.config().api_key2;