Why is a new site not being created in the github page?

Question

GitHub

Why is a new site not being created in the github page? Here actually did a repository through the terminal! But another site with my nickname works.

Answer 1

Because the repository should be called USERNAME.github.io.
And if you do not want to name the repository USERNAME.github.io, then create the test repository, make a gh-pages branch and put the site there, then your site will be available at the link USERNAME.github.io/test.
That is, one user has access to pages with a default domain only USERNAME.github.io.
On gitlab the situation is better, there you can create groups and projects for pages, then the address will be GROUP.gitlab.com or PROJECT.gitlab.com

Answer 2

I will add that on github you can also create an “organization” with any unoccupied name and get a site like ORGANISATION.github.io for it