It may be a little confusing when you follow the AstroJS official guide to deploy your blog on GitHub. Don't worry, I found an easier way. Follow these steps:

• Choose a theme.

I like the Dante theme

• Rename the repository to {username}.github.io

As I did with zwd321081.github.io.This is crucial because Github pages has specific naming rules

• Go to the Actions tab and search for the Astro workflow

• Making some modification to astro.yml

Remove the --site and --base options. This will result in your default URL being structured as https://{username}.github.io/{reponame}.
By removing these options, you eliminate the subpage path.

• Visit your page at the domain https://{username}.github.io, such as mine.