If you got the error code "WRONG_WEBSITE_SUBDOMAIN", then you entered the wrong URL.
The only avaliable URLs are: /nodeflow and /not_found, but not found is.. not found.
Subdomains are for features inside the website, eg YouTube has youtube.com/watch?=dQw4w9WgXcQ .
The avaliable subdomains in this site are /not_found, which is like I said, not found.
/nodeflow is the hidden scripting site. It is opensource, so you can get the files, but I am not sharing them anytime soon.