Only pull request authors can give upstream repository maintainers, or those with push access to the upstream repository, permission to make commits to their pull request's compare branch in a user-owned fork. To learn more about upstream repositories, see "About forks."
Pull request authors can give these permissions when they initially create a pull request from a user-owned fork or after they create the pull request. For more information, see "Creating a pull request from a fork."
You can set commit permissions when you first create a pull request from a fork. For more information, see "Creating a pull request from a fork." Additionally, you can modify an existing pull request to let repository maintainers make commits to your branch.
Enabling repository maintainer permissions on existing pull requests
On GitHub Enterprise Server, navigate to the main page of the upstream repository of your pull request.
Under the upstream repository name, click Pull requests.
In the list of pull requests, navigate to the pull request that you'd like to allow commits on.
On user-owned forks, if you do not want to allow anyone with push access to the upstream repository to make changes to your pull request, unselect Allow edits from maintainers.
Warning: If your fork contains GitHub Actions workflows, the option is Allow edits and access to secrets by maintainers. Allowing edits on a fork's branch that contains GitHub Actions workflows also allows a maintainer to edit the forked repository's workflows, which can potentially reveal values of secrets and grant access to other branches.