AWS Codepipeline not serving React from a PHP React Git repository

Question

I was setting up a Codepipeline for my GIT repository when I was new to AWS. My backend is PHP and my frontend is React. In order to use php as the backend, I first established an elastic beanstalk environment. Then I built my code using AWS code build, and at the end, I made a code pipeline.

The problem is that all I can see in the pipeline when I try to access it is php. Frontend for React is not loading.

I initially assumed that perhaps my React code was not being built, so I made a small tweak to it and received an update in AWS CodeBuild. So, I suppose that is not the issue.

If anyone requires any additional information, kindly let me know so that I may amend my query.

This is the yaml file I use.

version: 0.2
phases:
  install:
    # runtime-versions:
    #   nodejs: 14.11.0
    commands:
      # - echo installing node 16 
      # - curl -sL https://deb.nodesource.com/setup_16.x | bash
      # - apt install -y nodejs
      # - echo installing Yarn...
      # -  curl -sS https://dl.yarnpkg.com/debian/pubkey.gpg |  apt-key add -
      # - echo "curl -sS https://dl.yarnpkg.com/debian/ stable main"
      # - apt install --no-install-recommends yarn
  pre_build:
    commands:
      - echo Installing source NPM dependencies...
      - npm install 
  build:
    commands:
      - echo Testing ...
      # yarn test
      - echo Building ...
      - npm run build
  post_build:
    commands:
      - echo Build completed on `date`
# Include only the files required for your application to run.
artifacts:
  files:
    - "**/*"
base-directory : 'build'
    # - config.js
    # - index.js
    # - reset.js
    # - package.json
    # - node_modules/**/*