getting-started pages getting 404 error in header page

I was setting up the site, and deploy under Github pages. it works fine , but however when I tried to click in the navigation to `getting-started` link I got
```
404
Page not found

Go to the front page →
```

I got setup in `_config.yml` as the following:

`baseurl: /blog/`
`repo blog`

link https://skybulk.github.io/blog/tag/getting-started/