Unable to integrate ngx_uploader to angular 6. "Cannot find module 'ngx-uploader'"

Question

I am trying to use the ngx-uploader module for angular 6 but I keep getting the same error. I'm new with angular so I don't really understand what happens.

I install with.

npm install file:ngx-uploader 

and also

npm install "https://github.com/bleenco/ngx-uploader.git"

this created a folder in node_modules/ngx-uploader-demo

I tried to import

import { NgxUploaderModule } from 'ngx-uploader';
import { NgUploaderModule } from 'ngx-uploader/src/ngx-uploader/module/ngx-uploader.module'; 

What I can be doing wrong?

thanks a lot for any clue