Azure DevOps Fastlane Implementation in Pipeline

Hope you're doing well. I am working on implementing fastlane in azure devOps pipeline for a react native mobile app for iOS currently. I need to upload beta version to testFlight on Apple Connect using the code. I tried doing fastlane init and it doesn't seem to have create any difference when on pipeline so I went ahead and did fastlane init on mac and then pushed the changes to GitHub project. Here is the piece of my code. The code compiles but no apparent output is found. I'm new to the technology and have spent days over it. Please help me out.

pool:
  vmImage: 'macOS 10.14'


steps:
- script: echo Hello, world!
  displayName: 'Run a one-line script'

- script: |
    echo Add other tasks to build, test, and deploy your project.
    echo See https://aka.ms/yaml
  displayName: 'Run a multi-line script'

- task: UseRubyVersion@0
  inputs:
    versionSpec: '>= 2.4'

- task: NodeAndNpmTool@1
  inputs:
    versionSpec: '10.x'
  displayName: 'Install Node'

- script: npm install
  displayName: 'Install dependencies'

  
- task: InstallAppleCertificate@2
  inputs:
    certSecureFile: '*****.p12'
    keychain: 'temp'
  displayName: Install Apple Certificate
  
- task: InstallAppleProvisioningProfile@1
  inputs:
    provisioningProfileLocation: 'secureFiles'
    provProfileSecureFile: '*****'
  displayName: 'Install Apple Provisioning Profile'

- script:
    cd myFirstApp
    npm install
    cd ios
    xcode-select --install
    bundle install
    bundle exec fastlane beta
  displayName: 'Build iOS'