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