once you Created your app follow these steps:

1. npm install gh-pages --save-dev
2. Add properties to package.json file.
3. The first property we need to add at the top level homepage second we will define this as a string and the value will be "http://{username}.github.io/{repo-name}" {username} is your GitHub username, and {repo-name} is the name of the GitHub repository you created it will look like this :
   "homepage": "http://yuribenjamin.github.io/my-app"
   
   Second in the existing scripts property we to need to add predeploy and deploy.
   "scripts": {
   //... "predeploy": "npm run build",
   "deploy": "gh-pages -d build"
   }
4. Create a Github repository and initialize it and add it as a remote in your local git repository. Now, create a remote GitHub repository with your app name and go back initialize this git init add it as remote git remote add origin git@github.com:Yuribenjamin/my-app.git
5. Now deploy it to GitHub Pages. just run the following command : npm run deploy