I’ve started with Elm and want to get images from Trefle API when searched for plant but I keep getting the “Could not fetch image” error.
I do use my own access token but i replaced it here with “MY_API_TOKEN” to keep it private.
Can you help me to understand the problem in my code?
Thank you.

I’ve tried to get a more detailed error message but then my code crashed because I am quite new with using elm and in the webdevelopment field.

module Main exposing (..)

import Browser
import Html exposing (Html, button, div, img, input, text)
import Html.Attributes exposing (placeholder, src, type_)
import Html.Events exposing (onClick, onInput)
import Http
import Json.Decode exposing (Decoder, field, list, string)
import Maybe exposing (withDefault, map)


type alias Model =
    { searchTerm : String
    , imageUrl : String
    , error : String
    }


init : () -> ( Model, Cmd Msg )
init _ =
    ( { searchTerm = "", imageUrl = "", error = "" }, Cmd.none )


type Msg
    = UpdateSearchTerm String
    | FetchImage
    | ReceiveImage (Result Http.Error String)


update : Msg -> Model -> ( Model, Cmd Msg )
update msg model =
    case msg of
        UpdateSearchTerm term ->
            ( { model | searchTerm = term }, Cmd.none )

        FetchImage ->
            ( model, fetchPlantImage model.searchTerm )

        ReceiveImage result ->
            case result of
                Ok url ->
                    ( { model | imageUrl = url, error = "" }, Cmd.none )

                Err _ ->
                    ( { model | error = "Failed to fetch image." }, Cmd.none )


view : Model -> Html Msg
view model =
    div []
        [ input [ placeholder "Enter plant name", onInput UpdateSearchTerm ] []
        , button [ onClick FetchImage ] [ text "Search" ]
        , if model.imageUrl /= "" then
            img [ src model.imageUrl ] []
          else
            text ""
        , if model.error /= "" then
            div [] [ text model.error ]
          else
            text ""
        ]


fetchPlantImage : String -> Cmd Msg
fetchPlantImage searchTerm =
    let
        url =
            "https://trefle.io/api/v1/plants/search?token=MY_API_TOKEN&q=" ++ searchTerm

        decodeImageUrl : Decoder String
        decodeImageUrl =
            field "data" (list (field "image_url" string))
                |> Json.Decode.map (withDefault "" << map identity << List.head)
    in
    Http.get
        { url = url
        , expect = Http.expectJson ReceiveImage decodeImageUrl
        }


main : Program () Model Msg
main =
    Browser.element
        { init = init
        , update = update
        , subscriptions = _ -> Sub.none
        , view = view
        }