Getting issues while installing React Project on Windows system - node.js

Question

I am trying to install a React Web Application on my Windows system. It was working fine earlier but when I re-installed my Windows then it stopped working. I have already installed Node and Npm.
When I run the command npm install it goes well. But when I run the command npm start it throws the following error:
REACT_APP_ENV is not recognized as an internal or external command
Please see the attached image also:
I have tried a lot to find and fix the issue but nothing worked.
Here is package.json file content:
{
"name": "wm-webapp",
"version": "0.1.0",
"private": true,
"dependencies": {
"axios": "^0.18.0",
"gapi-client": "0.0.3",
"libphonenumber-js": "^1.7.7",
"moment": "^2.24.0",
"node-sass": "^4.11.0",
"react": "^16.7.0",
"react-bootstrap": "^0.32.4",
"react-dates": "^18.4.1",
"react-dom": "^16.7.0",
"react-facebook-login": "^4.1.1",
"react-google-login": "^5.0.0",
"react-places-autocomplete": "^7.2.0",
"react-redux": "^5.0.7",
"react-responsive": "^6.1.1",
"react-router": "^4.3.1",
"react-router-dom": "^4.3.1",
"react-router-redux": "^5.0.0-alpha.9",
"react-scripts": "2.1.3",
"react-select": "^1.2.1",
"react-stripe-elements": "^2.0.2",
"react-table": "^6.8.6",
"react-toastify": "^4.5.2",
"redux": "^4.0.1",
"redux-devtools-extension": "^2.13.7",
"redux-form": "^8.1.0",
"redux-form-input-masks": "^1.3.0",
"redux-logger": "^3.0.6",
"redux-saga": "^1.0.0",
"redux-thunk": "^2.3.0",
"store": "^2.0.12",
"styled-components": "^4.1.3"
},
"scripts": {
"start:env": "env-cmd .env.${REACT_APP_ENV} react-scripts start",
"start": "REACT_APP_ENV=dev npm run start:env",
"start:test": "REACT_APP_ENV=test npm run start:env",
"build:env": "env-cmd .env.${REACT_APP_ENV} react-scripts build",
"build": "REACT_APP_ENV=test npm run build:env",
"build:prod": "REACT_APP_ENV=prod npm run build:env",
"test": "react-scripts test",
"eject": "react-scripts eject",
"deploy": "aws s3 cp build s3://test.washmix.com/ --recursive --profile washmix",
"format": "prettier --write --single-quote --tab-width=2 --print-width=80"
},
"eslintConfig": {
"extends": "react-app"
},
"browserslist": [
">0.2%",
"not dead",
"not ie <= 11",
"not op_mini all"
],
"devDependencies": {
"axios-mock-adapter": "^1.16.0",
"env-cmd": "^8.0.2",
"husky": "^1.3.1",
"prettier": "^1.16.1"
}
}

Answer 1

Already late to answer but for people searching for the answer..
For Windows (cmd.exe) :
'set "REACT_APP_ENV=dev" && npm run start'
For Windows (Powershell) :
'($env:REACT_APP_ENV = "dev") -and (npm start)'
For Linux, macOS (Bash) :
'REACT_APP_ENV=dev npm start'
You can anytime get thing variable with process.env.REACT_APP_ENV

Answer 2

You must change all environment variables in your package.json for:
Set NAME_VARIABLE=VALUE
Ex:
"start": "Set REACT_APP_ENV=dev&& npm run start:env",

Answer 3

If you're running on windows, remember to leave no space between the commands and &&.
So the start script will be :
"start-staging":"set REACT_APP_ENV=staging&&react-scripts start"

Answer 4

In script-> start, write cross-env in starting of the value.
After that
Run: npm install.
And you are ready to go