Connect my custom domain (bought on Jimdoo) to my Github

[thehairlounge24]

Hey guys.

I'm 2 days on github, i created my first website for a friend of mine. She first did her own website on jimdoo and purchased the domain from jimdoo. Now if you want to transfer the domain, you click the button and you just get a authentification-code. I don't know what to do with this code, where do i put this in on github?

And anyone also knows where the DNS-Settings are on jimdoo?

I'm so lost, please help :(