如何在AWS EC2中为React＆Go设置环境变量

I've made React & Go product in local. And I'm going to deploy it to AWS EC2.

To work in AWS EC2, I need to set environment variables for some secret information.

I've already set env variables for local environment. But I'm not sure about env variables working for production environment(AWS EC2).

I already set env. file for local environment. But not sure how to set environment variables in ec2.

I use environment variables for axios, firebase and mysql.

//axios
   const client = axios.create({
      baseURL: process.env.REACT_APP_API_URL,
    });
    client
      .get('/api/articles')
      .then(response => {
        this.setState({articles: response.data});
      })
      .catch(response => console.log('ERROR!! occurred in Backend.'));

//firebases
const firebaseConfig = {
  apiKey: process.env.REACT_APP_FIREBASE_API_KEY,
  authDomain: process.env.REACT_APP_FIREBASE_AUTH_DOMAIN,
  databaseURL: process.env.REACT_APP_FIREBASE_DATABASE_URL,
  projectId: process.env.REACT_APP_FIREBASE_PROJECT_ID,
  storageBucket: '',
  messagingSenderId: process.env.REACT_APP_FIREBASE_MESSAGING_SENDER_ID,
  appId: process.env.REACT_APP_FIREBASE_APP_ID,
};

firebase.initializeApp(firebaseConfig);

export default firebase;

//mysql
    err := godotenv.Load()
    if err != nil {
        //TODO production

    }
    db, err := sql.Open("mysql", os.Getenv("MYSQL_USER")+":"+os.Getenv("MYSQL_PASSWORD")+"@tcp(localhost:3306)/article")
    if err != nil {
        panic(err.Error())
    }

    defer db.Close()

    err = db.Ping()
    if err != nil {
        panic(err.Error())
    }

Here is the github. https://github.com/jpskgc/article

I'm going to deploy this React & Golang product in AWS EC2. But I'm not sure how to set environment variables.