My steps are:
npm run build
Then
"homepage": "https://parthaaaaa.github.io/firstwebapp/",
"predeploy": "npm run build",
"deploy": "gh-pages -d build"
in package.json file
Then
npm install --save-dev gh-pages
Then
In Github repository.. I selected gh pages branch
Finally,
npm run deploy
but I'm getting a blank page app runs fine in local host..
Help..
In your package.json homepage
is not correct, so it is messing up the build.
Change
"homepage": "https:Parthaaaaa.github.io/firstwebapp",
to
"homepage": "https://parthaaaaa.github.io/firstwebapp",
Then try building and deploying again.
Documentation on Building for Relative Paths