How to use in Angular 7

[CarlosMal]

(I'm sorry for my English)
I am trying to use ifVisible in angular 7 but I can't use it, can someone help me please?
What am I missing or what do I fail?

install it with npm and ifvisible,

in my package.json
"ifvisible": "1.1.0",

in my angular.json

"scripts": [
            "./node_modules/ifvisible/src/ifvisible.js"
          ],

my .ts

import {IfVisible} from "ifvisible / src / ifvisible.js";
const ifvisible = new IfVisible (window, document);

using it in a function:

 ifvisible.setIdleDuration (300);
   console.log (ifvisible);

I get this error:

TypeError: ifvisible_src_ifvisible_js__WEBPACK_IMPORTED_MODULE_6 __. IfVisible is not a constructor
TypeError: ifvisible_src_ifvisible_js__WEBPACK_IMPORTED_MODULE_6 __. IfVisible is not a constructor

[NevenLiang]

@CarlosMal Theres is no needs to add it to angular.json. You can use it in Angular like this.

import * as ifvisible from 'ifvisible.js';

ifvisible.on('idle', () => {
  console.log('it is idle now ...');
});

ifvisible.on('wakeup', () => {
  console.log('it wakes up!');
});