Here is the link:
http://myOneboxURL/client/registration/?Parameters that can be added to links:
ref is the contact ID
refexternal is the External ID of the contact
Let's say we have a system, its address is: onebox.ua
And we have a client his ID = 5
He invites a second client and wants to give him a link, it will be like this:
http://onebox.ua/client/registration/?ref=5After registering the second client in your onebox personal account, he will have the "Recommended" field filled in, it will indicate the contact who invited, that is, the contact with ID = 5.