Problem with Phoenix and Elm with Webpack [SOLVED]

Hi, I try to use Elm with Phoenix .
In files I have
package.json :

"dependencies": {
    "elm": "^0.19.1-3",
    "elm-webpack-loader": "^6.0.1",
    "phoenix": "file:../deps/phoenix",
    "phoenix_html": "file:../deps/phoenix_html"
  },

in webpack.config.js

{
        test: /\.elm$/,
        exclude: [/elm-stuff/, /node_modules/],
        use: {
           loader: 'elm-webpack-loader',
           options: {
              cwd: path.resolve(__dirname, 'elm')
           }
        }
      }

in js/app.js

import { ELm } from "../elm/src/Main.elm";
  
Elm.Main.init({
    node: document.getElementById('elm-main')
}) 

Elm file (in asset/elm/src/Main.elm) :

module Main exposing (main)
import Html exposing (text)
main =
    text "Hello Elm and Phoenix!" 

and in index.html.eex

<div id="elm-main"></div>

All is compiled well ,

[./elm/src/Main.elm] 86.6 KiB {./js/app.js} [built]
[./js/app.js] 611 bytes {./js/app.js} [built]
   [0] multi ./js/app.js 28 bytes {./js/app.js} [built]
    + 2 hidden modules

but I’ve got error in JS console on website:

Elm.Main.init({
  node: document.getElementById('elm-main')
})
Uncaught ReferenceError: Elm is not defined

so ELM is not working. I have no idea where the problem is . Thanks in advance for help.