Build and Deploy only on PR request Accept using circle ci

We are testing a Project with the workflow using GitHub, CircleCI and deployment to Pantheon upstream. At present, We could see that the CircleCI pipeline gets triggered when a Pull request is created. What we are trying to achieve is

Need to run the pipeline which includes the PHP code sniffer and other tests when a pull request is created by developer. Once the pull request is created, the pipeline will be executed and the output of the tests will be shown in CircleCI and GitHub.

As the next step, After Manual code review, the TL approves the pull request, The developers feature branch will be merged to the main branch (May be the ‘develop’ branch) and we will need the pipeline to be trigger but not with the tests but with the ‘build’ and ‘deploy’ part in the pipeline. How to trigger the pipeline when a PR request is accepted?

So,

When a Pull request is created - The ‘cypress tests’ part of the pipeline needs to be executed When a Pull request is accepted - The ‘build’ and the ‘deployment’ part of the pipeline needs to be executed. Please let us know how we could achieve this?

from Build and Deploy only on PR request Accept using circle ci