If you want to update the latest:

npm install -g npm@latest

Or

npm i -g npm@latest

If node_modules's folder existed before you update the latest npm version in project folder (your-app).

Remove by cmd:

rm -r node_modules

npm install

Or

 npm i

(note: install the node_modules to build production and push on github to create github pages)

cd your-app
npm i gh-pages --save-dev

• "homepage", "private", "dependencies", "scripts", "eslintConfig"

• Add .gitignore to ignore node_modules push on to github

npm run deploy

git init
git remote add origin [email protected]:[your-user-account/your-app (replace by your link)]

git clone [email protected]:[your-user-account/your-app]

Copy all files from your project's folder into your-app folder

git add .
git commit -m "your note in this commit"

• If the first time you push on git

git push -u origin master

• If the second and then (you are on branch master)

git push