I'm trying to follow along this article on how to create a mutation on a rails server using GraphQl <https://www.howtographql.com/graphql-ruby/4-authentication>

However, I'm stuck at the CreateUser Mutation step, I get the follow error hash when trying it out in GraphiQL:

```
{
  "errors": [
    {
      "message": "Field 'createUser' is missing required arguments: input",
      "locations": [
        {
          "line": 45,
          "column": 3
        }
      ],
      "path": [
        "mutation CreateUser",
        "createUser"
      ],
      "extensions": {
        "code": "missingRequiredArguments",
        "className": "Field",
        "name": "createUser",
        "arguments": "input"
      }
    },
    {
      "message": "Field 'createUser' doesn't accept argument 'username'",
      "locations": [
        {
          "line": 46,
          "column": 5
        }
      ],
      "path": [
        "mutation CreateUser",
        "createUser",
        "username"
      ],
      "extensions": {
        "code": "argumentNotAccepted",
        "name": "createUser",
        "typeName": "Field",
        "argumentName": "username"
      }
    },
    {
      "message": "Field 'createUser' doesn't accept argument 'authProvider'",
      "locations": [
        {
          "line": 47,
          "column": 5
        }
      ],
      "path": [
        "mutation CreateUser",
        "createUser",
        "authProvider"
      ],
      "extensions": {
        "code": "argumentNotAccepted",
        "name": "createUser",
        "typeName": "Field",
        "argumentName": "authProvider"
      }
    },
    {
      "message": "Variable $username is declared by CreateUser but not used",
      "locations": [
        {
          "line": 44,
          "column": 1
        }
      ],
      "path": [
        "mutation CreateUser"
      ],
      "extensions": {
        "code": "variableNotUsed",
        "variableName": "username"
      }
    },
    {
      "message": "Variable $email is declared by CreateUser but not used",
      "locations": [
        {
          "line": 44,
          "column": 1
        }
      ],
      "path": [
        "mutation CreateUser"
      ],
      "extensions": {
        "code": "variableNotUsed",
        "variableName": "email"
      }
    },
    {
      "message": "Variable $password is declared by CreateUser but not used",
      "locations": [
        {
          "line": 44,
          "column": 1
        }
      ],
      "path": [
        "mutation CreateUser"
      ],
      "extensions": {
        "code": "variableNotUsed",
        "variableName": "password"
      }
    }
  ]
}

```

I just followed the code in the article, my files:

**create\_user.rb**

```
module Mutations
  class CreateUser < BaseMutation
    # often we will need input types for specific mutation
    # in those cases we can define those input types in the mutation class itself
    class AuthProviderSignupData < Types::BaseInputObject
      argument :credentials, Types::AuthProviderCredentialsInput, required: false
    end

    argument :username, String, required: true
    argument :auth_provider, AuthProviderSignupData, required: false

    type Types::UserType

    def resolve(username: nil, auth_provider: nil)
      User.create!(
        username: username,
        email: auth_provider&.[](:credentials)&.[](:email),
        password: auth_provider&.[](:credentials)&.[](:password)
      )
    end
  end
end

```

**user\_type.rb**

```
module Types
  class UserType < BaseObject
    field :id, ID, null: false
    field :email, String, null: false
    field :username, String, null: false
    field :photo, String, null: true
    field :phone, String, null: false
    field :island, IslandType, null: false, method: :island
    field :archipel, ArchipelType, null: false, method: :archipel

    field :created_at, String, null: false
    field :updated_at, String, null: false
  end
end

```

I have no clue where this 'input' thing is coming from.