When it comes to finding a solution, Necessity is the driving factor. As you all know, we recently launched our website. Little did we know, when searching for Stackrole found two website being indexed on search engine. One being the custom domain and the other is Netlify subdomain.\ \ Best way fix this is to add 301 redirect for Netlify subdomain. You can add the following code to your netlify.toml in your websites root directory.

[[redirects]]
  from = "https://example.netlify.app"
  to = "https://example.com/"
  status = 301
  force = true

Replace the example with your site name.