Problem with Lambda mutation

Users GraphQL
, ,
4

Thease are the types and mutation im using in schema regarding this problem

type User @secret(field: "password") {
  username: String! @id
  email: String!
  characters: [Character] @hasInverse(field: owner)
  role: UserRole! @search
}

enum UserRole {
  USER
  ADMIN
}

type Character
  @auth(
    query: {
      rule: """
      query ($USER: String!) {
          queryCharacter{
              owner(filter:{username: { eq: $USER }}){
                username
              }
          }
      }
      """
    }
  ) {
  id: ID!
  name: String!
  race: String!
  owner: User! @hasInverse(field: characters)
}

type Mutation {
  signup(
    username: String!
    email: String!
    password: String!
    password2: String!
  ): signupPayload! @lambda
}

type signupPayload {
  username: String
  token: String
}

And this is what im having in insomnia:

mutation addUser(
  $user: AddUserInput!,
){
 addUser(input: [$user]){
  user{
    username
    role
  }
}

variables:

{
	"user": {
		"username": "user",
		"email": "user@email.com",
		"characters": [],
		"password": "123456",
		"role": "USER"
	}
}