That feeling when you are looking out for two days and find it like this: just remove .js from "main": "dist/index.js" in package.json and everything works fine!
"main": "dist/index",
UPD: this answer relative if you have your own npm package, if not – see my answer below.
And if above answer not resolved import your module, try just add typings in package.json:
"main": "dist/index",
"typings": "dist/index",
Of course, here folder dist – it’s where stores your module’s files.
