Hi@akhtar,
The following create-pull-request example creates a pull request named 'My Pull Request' with a description that targets the 'MyNewBranch' source branch and is to be merged to the default branch 'master' in an AWS CodeCommit repository named 'MyDemoRepo'.
$ aws codecommit create-pull-request \
--title "My Pull Request" \
--description \
--client-request-token 123Example \
--targets repositoryName=MyDemoRepo,sourceReference=MyNewBranch