Checking this option will disable regular polling (cron) for changes in GitHub and will try to create a GitHub hook. Creating a GitHub hook requires that the user which is specified in the GitHub Pull Request Builder configuration has admin rights to the specified repository.
By default, GitHub hooks created this way will have SSL certificate verification enabled. To disable SSL certificate verification in these GitHub hooks, start Jenkins with system property org.jenkinsci.plugins.ghprb.GhprbRepository.webhook.insecure set to true.
If you want to create a hook manually set it for event types: issue_comment, pull_request and url < your jenkins server url >/ghprbhook/. The url should be composed of your full jenkins server url plus the ending /ghprbhook/ path. If your jenkins server is just a domain like https://jenkins.yourcompany.com then the url would look like https://jenkins.yourcompany.com/ghprbhook/. If your jenkins server is accessed at a path off of a domain like https://yourcompany.com/jenkins then the url would look like https://yourcompany.com/jenkins/ghprbhook/
. Your Jenkins server must be accessible from internet.