I'm kinda confused how to properly export my own JS library (for Svelte).
When I import the library on a local project (example local project) then everything works just fine, but when I import it in a online editor like Svelte REPL or CodeSandbox it just won't work, because the module can't be found.

The file that exports: https://github.com/DanielSharkov/svelte-router/blob/master/src/index.js

Replication on CodeSandbox: https://codesandbox.io/s/jovial-morning-5o7xr?file=/router.js

To replicate it on Svelte REPL (I can't safe to share it, because of the error):

<script>
    import {SvelteRouter} from '@danielsharkov/svelte-router'
    console.log(SvelteRouter)
</script>

For more details of the library you may inspect the repository: https://github.com/DanielSharkov/svelte-router

The files src/router.js and src/router.mjs aren't in the repository, as these are builds of index.ts.