Cannot install package

<template> 

    <div id="app"> 

    <ejs-accordion > 

            <e-accordionitems> 

        <e-accordionitem expanded='true' header='ASP.NET' content='Microsoft ASP.NET is a set of technologies in the Microsoft .NET Framework for building Web applications and XML Web services.'></e-accordionitem> 

        <e-accordionitem header='ASP.NET MVC' content='The Model-View-Controller (MVC) architectural pattern separates an application into three main components: the model, the view, and the controller.'></e-accordionitem> 

        <e-accordionitem header='JavaScript' content='JavaScript (JS) is an interpreted computer programming language.It was originally implemented as part of web browsers so that client-side scripts could interact with the user, control the browser, communicate asynchronously, and alter the document content that was displayed.'></e-accordionitem> 

      </e-accordionitems> 

    </ejs-accordion> 

  </div> 

</template> 

<script> 

import Vue from 'vue'; 

import { AccordionPlugin } from '@syncfusion/ej2-vue-navigations'; 

Vue.use(AccordionPlugin); 

export default { 

  name: 'app', 

} 

</script> 

<style> 

  @import "/node_modules/@syncfusion/ej2-base/styles/material.css"; 

  @import "/node_modules/@syncfusion/ej2-vue-navigations/styles/material.css"; 

</style>