Reactでnpm startでローカル立ち上げ時のポート番号を指定する方法

package.jsonの、 start": "react-scripts start"PORT=3001 を追加

"scripts": {
  "start": "PORT=3001 react-scripts start",
  "build": "react-scripts build",
  "test": "react-scripts test",
  "eject": "react-scripts eject"
},