You need to install GitHub Pages package as a dev-dependency.

cd ./into/your-app-folder
npm install gh-pages --save-dev

Add properties to package.json file.

The first property you need to add at the top level homepage, second you must define this as a string and the value will be "https://{your-username}.github.io/{repo-name}" , {repo-name} is the name of the GitHub repository you created it will look like this :

"homepage": "http://joedoe.github.io/your-app"

Second in the existing scripts property you need to add predeploy and deploy.

"scripts": {
//...
"predeploy": "npm run build",
"deploy": "gh-pages -d build"
}

If you pushed everything already to Github, the last step is deploying. One liner:

npm run deploy

With this Github will create a new branch called gh-pages, and will be available online. Hope I could help and will work accordingly.

If you stuck, you can look it up on the official docs of React. Deployment Documentation of React

Once on a deployment I had some issues with the official documentation, and I had to delete my username from the "homepage" property in order to make it work. Although I suggest you first do by the docs, and if you encounter problems, you might can give a try.

To use React on GitHub Pages, you'll need to follow these steps:

Create a new repository on GitHub: Go to GitHub and create a new repository for your React project.

Set up your local development environment: Make sure you have Node.js and npm (Node Package Manager) installed on your computer. You can download them from the official Node.js website if you don't have them already.

Create a new React app: Open your terminal or command prompt and navigate to the directory where you want to create your React app. Run the following command to create a new React app:

npx create-react-app my-app
This will create a new directory called my-app with a basic React project structure.

Build your React app: Once the app is created, navigate into the project directory by running cd my-app. Then, run the following command to build your React app:

npm run build
This will create an optimized production build of your React app in the build directory.

Deploy to GitHub Pages: Install the gh-pages package, which will help you deploy your React app to GitHub Pages. Run the following command:

npm install gh-pages --save-dev
Configure your package.json file: Open the package.json file in your project directory and add the following properties at the top level:

"homepage": "https://your-username.github.io/your-repo-name",
"scripts": {
"predeploy": "npm run build",
"deploy": "gh-pages -d build"
}
Replace your-username with your GitHub username and your-repo-name with the name of your repository.

Deploy your app: In your terminal or command prompt, run the following command to deploy your React app to GitHub Pages:

npm run deploy
This will create a new branch called gh-pages in your repository and push the built files from the build directory to that branch.

Enable GitHub Pages: Go to your repository on GitHub and navigate to the "Settings" tab. Scroll down to the "GitHub Pages" section and select the gh-pages branch as the source for your GitHub Pages site.

Access your deployed app: After a few moments, your React app should be deployed and accessible at the URL mentioned in the "GitHub Pages" section of your repository settings.

That's it! Your React app is now deployed on GitHub Pages. Anytime you make changes to your app, repeat steps 4 and 7 to rebuild and redeploy your app.

Hope you got your answer.