How to confirm the registration and set initial Password

no doesn't work. Bad Request. No wonder since the model looks like this:

Register {
   email (string): Email address of the new user. ,
   first_name (string, optional): First name of the new user. ,
   last_name (string, optional): Last name of the new user. ,
   display_name (string, optional): Full display name of the new user. ,
   new_password (string, optional): Password for the new user. ,
code (string, optional): Code required with new_password when using email confirmation.
}