no provider for BarcodeScanner

You need to set the scanner as provider in app.module.ts

import { BarcodeScanner } from '@ionic-native/barcode-scanner';

@NgModule({
  ...

  providers: [
    ...
    BarcodeScanner
    ...
  ]
  ...
})
export class AppModule { }

Reference: Add Plugins to Your App's Module here

UPDATE: From your package.json it looks like you have installed older ionic-native - 2.4.1.Remove it and do:

npm install --save @ionic-native/core

I have same issue with ionic cli 3.9.2 & solved using npm i @ionic-native/barcode-scanner@beta --save.

import { BarcodeScanner } from "@ionic-native/barcode-scanner/ngx";

@NgModule({
  ...

  providers: [
    ...
    BarcodeScanner
    ...
  ]
  ...
})
export class AppModule { }