Your Prettifier installation has authorization to access only the repositories inside your GitHub organization. Pull requests from forks contain changes made in repositories owned and managed by people outside your organization. Your Prettifier installation cannot (and should not) commit into these repositories directly. Prettifier checks the formatting of these changes once they are proposed to your organization via a pull request. If it finds mismatching formatting, Prettifier notifies the contributor about your project’s formatting guidelines and a list of files that have invalid formatting. You can customize this message via the configuration file
Prettifier adds only one such message per pull request, even if later commits contain more formatting mismatches.