Import js file to theme.js

[compsoul.dev]

import Carousel from "./modules/carousel";

(function() {
  console.log(new Carousel("body"));
})();

I have this code in theme.js and in modules folder this one:

export default class Carousel {
Class stuff...
}

Why this code dosnt work? Errors:
FF: SyntaxError: import declarations may only appear at top level of a module
Chrom: Uncaught SyntaxError: Unexpected identifier