Issue with the BarcodeScanner plugin

Hi, i have a problem with BarcodeScanner plugin:

  1. When i try to make import
    import { BarcodeScanner } from ‘@ionic-native/barcode-scanner’;

in the constructor i can see “Cannot find name ‘BarcodeScanner’”, before i have intalled the plugin this way:

ionic cordova plugin add phonegap-plugin-barcodescanner
npm install @ionic-native/barcode-scanner

  1. The editor show me a observation, for example, to use:
    import { BarcodeScanner } from ‘@ionic-native/barcode-scanner/ngx’;

I try this, but in the browser, i get this error:

HomePage.html:10 ERROR TypeError: Object(…) is not a function
at BarcodeScanner.scan (index.js:34)
at HomePage.webpackJsonp.272.HomePage.scan (home.ts:19)
at Object.eval [as handleEvent] (HomePage.html:10)
at handleEvent (core.js:13589)
at callWithDebugContext (core.js:15098)
at Object.debugHandleEvent [as handleEvent] (core.js:14685)
at dispatchEvent (core.js:10004)
at core.js:10629
at HTMLButtonElement. (platform-browser.js:2628)
at t.invokeTask (polyfills.js:3)

¡help please!

PD: Sorry, i do not speak English, i hope understand me and help me. thanks a lot