npm install -g nodemon
npm install -g nodemon --save
npm install --save-dev nodemon
npm install -g nodemon@debug

npm install -g --force nodemon

npm install -g nodemon
# or if using yarn
yarn global add nodemon

"scripts": {
    "serve": "nodemon server.js"
  },

npm run serve

# without adding serve in package.json
yarn run nodemon server.js
# with serve script in package.json
yarn run serve

node_modules/.bin/nodemon

npm install nodemon -g