Uncaught TypeError: _modules_selector_gen_index__WEBPACK_IMPORTED_MODULE_1___default(...).getCssSelector is not a function

[nxvinh222]

I'm trying to import this library into my script using :
import CssSelectorGenerator from './modules/selector-gen/index';
(I copied index file from build folder)
But it seem like not working at all. For some reason I cannot use npm, anyone ever did this before? Any help would be appreciated.