elm reverse, but it's not working

reverse.elm

import Browser
import Html exposing (Html, Attribute, div, input, text, button)
import Html.Attributes exposing (..)
import Html.Events exposing (onClick)



-- MAIN


main =
  Browser.sandbox { init = init, update = update, view = view }



-- MODEL


type alias Model =
    { content : String,
      reversed : String
    }


init : Model
init =
    { content = "",
      reversed = ""}



-- UPDATE


type Msg = Reverse


update : Msg -> Model -> Model
update msg model =
  case msg of
    Reverse ->
        { model | reversed = String.reverse model.content }



-- VIEW


view : Model -> Html Msg
view model =
  div []
    [ input [placeholder "Text to reverse"] []
    , button [ onClick Reverse ] [ text "Reverse" ]
    , div[] [ text model.reversed ]
    ]

nothing happens when clicking on the button