Go to your repository on GitHub.com and click on the "Settings" tab.
Ensure your repo is public and turn on GitHub Pages. It should say "Your GitHub Pages site is currently being built from the master branch."
Let's deploy from the gh-pages branch, detailed here: Create React App Docs - Deployment - GitHub Pages Tutorial.
Add the homepage to package.json, for example with mine:
"homepage": "https://github.com/hashbangash/dojo",
Edit your scripts to include the deployment:
"scripts": {
"start": "parcel serve index.html",
"build": "parcel build index.html --public-url /<your_repo_name>/",
"predeploy": "yarn build",
"deploy": "gh-pages -d dist"
}
The build script was updated with the --public-url tag and the relative path of the GitHub repository. This parcel and gh-pages help page on the parcel-bunder GitHub issue had the key info needed to alter the build script.
Note that the deploy script uses the dist folder because this is the name of the directory parcel uses during the build process.
Then, ensure on your GitHub repo in Settings that GitHub Pages is building from the gh-pages branch and not the master branch.
Great! Now you can visit your hosted page! Mine is at https://hashbangash.github.io/dojo/.