Click Build settings on App settings page.
You will see a build specification file that is named amplify.yml, you can edit this file to specify how Amplify builds your repository.
When your repository has new commit, Amplify will be triggered and run the amplify.yml. The pipeline will be shown for you after Provison, Build, Deploy & Verify
Amplify allows to you store environment variables (secret key, version name, …). You can specify the variable for a branch or all. Click Manage variables to see your variables and add new.
When you connect repository and branch to Amplify, you will have a URL for your branch. You can see your URL in Domain management page.
You can also use your own domain with free HTTPS to provide a secure, friendly URL for your app. Register your domain on Amazon Route53 for a one-click setup, or connect any domain registered on a 3rd party provider.
Click Add domain to custom friendly URL for your app.
You will know when your app will be built and when it done by add new email to Amplify notification.
Try to add your email and confirm the subscriptions.
Go to next chapter to change something.