Install dependencies

Execute the following steps from your Cloud9 terminal.

cd ~/environment
mkdir frontend
touch frontend/package.json
nvm install lts/erbium
nvm use lts/erbium

Then paste the following dependency declaration into frontend/package.json, remembering to save the file afterwards:

{
  "name": "frontend",
  "version": "0.1.0",
  "private": true,
  "dependencies": {
    "@apollo/client": "^3.1.3",
    "@apollo/react-hooks": "^3.1.5",
    "@aws-amplify/auth": "^3.3.4",
    "@aws-amplify/core": "^3.4.5",
    "@testing-library/jest-dom": "^5.11.6",
    "@testing-library/react": "^11.2.0",
    "@testing-library/user-event": "^12.2.2",
    "apollo-client": "^2.6.10",
    "apollo-link": "^1.2.14",
    "apollo-link-ws": "^1.0.20",
    "aws-appsync-auth-link": "^2.0.2",
    "aws-appsync-subscription-link": "^2.2.0",
    "graphql": "^15.3.0",
    "graphql-tag": "^2.11.0",
    "moment": "^2.27.0",
    "react": "^16.8.0",
    "react-apollo": "^3.1.5",
    "react-dom": "^16.8.0",
    "react-scripts": "3.4.4",
    "web-vitals": "^0.2.4"
  },
  "scripts": {
    "start": "react-scripts start",
    "build": "react-scripts build",
    "test": "react-scripts test",
    "eject": "react-scripts eject"
  },
  "eslintConfig": {
    "extends": [
      "react-app",
      "react-app/jest"
    ]
  },
  "browserslist": {
    "production": [
      ">0.2%",
      "not dead",
      "not op_mini all"
    ],
    "development": [
      "last 1 chrome version",
      "last 1 firefox version",
      "last 1 safari version"
    ]
  }
}

Enter the frontend folder and install some additional dependencies.

nvm use lts/erbium
cd ~/environment/frontend
npm install

This will take a few minutes and eventually return with a message like this.

...
added 2000 packages from 875 contributors and audited 2007 packages in 40.865s

77 packages are looking for funding
  run `npm fund` for details

found 0 vulnerabilities