I have two branch master and dev. Can anyone help me how can do automerge.My requirement is any changes come in master branch will come automatically in dev branch

I have two branch master and dev. Can anyone help me how can do automerge.My requirement is any changes come in master branch will come automatically in dev branch

https://docs.github.com/en/github/collaborating-with-pull-requests/incorporating-changes-from-a-pull-request/automatically-merging-a-pull-request

You can increase development velocity by enabling auto-merge for a pull request so that the pull request will merge automatically when all merge requirements are met.

click here for more info