Call a GraphQL mutation with @hasMany

I'm using DynamoDB of AWS and i'm trying to insert item with relations (hasMany). When i'm trying to create item with relations it returns error:

"The variables input contains a field name 'contacts' that is not defined for input object type 'CreateBookingInput' "

Here is the definition of my models where you can see the relations

    type Traineeship @model @auth(rules:[{allow:public}]){
  traineeshipID: ID! @primaryKey
}

type Booking @model @auth(rules:[{allow:public}]){
  bookingID: ID! @primaryKey
  traineeship: Traineeship @hasOne
  contacts:[BookingContact] @hasMany
}

type BookingContact @model @auth(rules:[{allow:public}]){
  bookingContactID: ID! @primaryKey
}

And here is the mutation use to insert

    export const createBooking = /* GraphQL */ `
  mutation CreateBooking(
    $input: CreateBookingInput!
    $condition: ModelBookingConditionInput
  ) {
    createBooking(input: $input, condition: $condition) {
      bookingID
      traineeship {
        traineeshipID
        title
        description
        fulldesc
        place
        from
        to
        price
        img
        horaire
        garderie
        age
        full
        createdAt
        updatedAt
      }
      email
      tel
      firstname
      name
      birthdate
      address
      zipcode
      city
      Remark
      submitedDate
      validatedDate
      validated
      contacts {
        items {
          bookingContactID
          firstname
          name
          phone
          parent
          createdAt
          updatedAt
          bookingContactsId
        }
        nextToken
      }
      createdAt
      updatedAt
      bookingTraineeshipId
    }
  }
`;

As you can see contacts is define in createBooking. If i remove this property it works correctly.

THanks for your help