Cannot read properties of undefined (reading 'includes')

I am trying to create a graphql to create a user and trying this in the playground:

mutation(
  $email: String!
  $password: String!
  $username: String!
) {
  createUser(
    data: {
      email: $email
      password: $password
      username: $username
    }
  )
  {
    id
    username
    email
  }
}

and pass variables:

{   "email": "email@email.com",   "password": "1234567",   "username": "username" }

but I get this error:

{
  "errors": [
    {
      "message": "Cannot read properties of undefined (reading 'includes')",
      "locations": [
        {
          "line": 2,
          "column": 3
        }
      ],
      "path": [
        "createUser"
      ],
      "extensions": {
        "name": "TypeError"
      }
    }
  ],
  "data": {
    "createUser": null
  }
}

what is causing this error and where can I start debugging?

it was because of a hook mistake