API to Create a User

I'm trying to create a user from the API using:

POST: https://karaokeworld.net/restful_api/user

I'm sending the params:
'full_name': fullname,
'user_name': username,
'email': email,
'password': password,
'access_token': access_token

But I'm getting this error:

"message": "You cannot register an account with an access token of an user."

What am I missing? How do you create a user if you don't have an access token for that user??