I will move this over to the Game Help board since you are asking for assistance.
The reason your friend cannot create an account is because we have temporarily taken the Registration offline due to site updates, as MorgaWolf has explained above. We are looking into opening up the Registration again but are not yet able to do so until we complete our site renovations. We are doing everything that we can to look into this and make it so that users can create new accounts, but until then, there is no way to create a new account. We will be sure to notify users when we have brought it back online, but until then, please try to be patient with us. <3
I will be locking this topic, since your question has been answered. If you have any further questions regarding the Registration, feel free to message a staff member.