Gem doesn't work with latest version of RoR

rails g cookies_eu:install

helper doesn't work as well, it expects application.js to be in /app/assets/javascripts/application.js

and generates error

/app/assets/javascripts/application.js does not appear to exist

After that, when loading page, banner can't be dismissed because of

application.js:1 Uncaught Error: Cannot find module 'cookies_eu'
    at webpackMissingModule (application.js:1)
    at Module.<anonymous> (application.js:1)
    at Module../app/javascript/packs/application.js (application.js:41)
    at __webpack_require__ (bootstrap:19)
    at bootstrap:83
    at bootstrap:83