CNAME and Custom Servers


I’m running an experimental server at home.

Now I can access it at from outside my home network without issues by using the Custom DNS Record and setting the Type to CNAME, then pointing that ty my name.

I can access wild card domains also I.E. * so stuff like, ect all work.

But if I try just It will not resolve to my home testing server.

And if I try to add the name (Blank) under add a custom DNS Record for I get
CNAME Records may only be used on sub-domains so How do I configure the root name ?