The GitHub Pages service is open to every user for domain name resolution and hosting of
username.github.io. If you are an ordinary user, the Github-Page service will only be open to public repositories. After the repositories are converted to private, Github-Page will stop parsing And updates; for student Pro and paid Pro users and above, the Github-Page service will provide services for both public and private repositories, but Travis CI is only free for public repositories. In summary, this article is for guys who want to use GitHub Pages service for private repositories.
P.S. Privatizing the repository hosting Github-Page can reduce privacy leakage. However, all files (of the deployment branch) can still be crawled/scanned.