Your have entered a valid Domain, but you have no account on this blog.

Based on what I see at your site it looks like you may have discovered the answer, but for the benefit of others, You’ll need a few things to make it work:

• You should have the URL of your domain name set in the URL field of your Public Profile on Github. (Inspecting the URL element on your profile page will reveal that it’s wrapped with a rel=”me”.)
• The homepage of your site should have a rel=”me” link pointing to your github account. eg: <a rel="me" href="https://github.com/USERNAME">Github</a> or if you don’t want it to be visible <link rel="me" href="https://github.com/USERNAME">

Now when you try to log in, you can just put your URL into the login box. You’ll be redirected to the IndieAuth site which will scan your site for the rel-me links and present you with options for logging in based on the compatible sites (Twitter works well too, though you can also use email and SMS among other options). Click on the github button and if you’re already logged in via github you’ll be redirected to your website as logged in.