Code Pipeline Trigger for GitHub version 2 (app-based) action via Cloudformation

Hello.

You can create a connection using "AWS::CodeStarConnections::Connection", but I don't think you can do things like GitHub authentication without operating from the management console.
https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-codestarconnections-connection.html

Perhaps the sample document below will be helpful for triggers.
https://docs.aws.amazon.com/codepipeline/latest/userguide/pipelines-filter-cfn.html

The above sample seems to be the content set by the parameter "Triggers" of "AWS::CodePipeline::Pipeline".
https://docs.aws.amazon.com/ja_jp/AWSCloudFormation/latest/UserGuide/aws-resource-codepipeline-pipeline.html#cfn-codepipeline-pipeline-triggers