After installation simply comment /rebase to trigger the action:

To configure the action simply add the following lines to your .github/main.workflow workflow file:

workflow "Automatic Rebase" {
  on = "issue_comment"
  resolves = "Rebase"
}

action "Rebase" {
  uses = "docker://cirrusactions/rebase:latest"
  secrets = ["GITHUB_TOKEN"]
}

It's possible to use author_association field of a comment to restrict who can call the action and skip the rebase for others. Simply add the following expression to the if statement in your workflow file: github.event.comment.author_association == 'MEMBER'. See documentation for a list of all available values of author_association.