<!-- sidebar element declaration -->
@{Html.EJS().Sidebar("default-sidebar").Type(Syncfusion.EJ2.Navigations.SidebarType.Push).Width("280px").Target(".maincontent").ContentTemplate(@<div>
    <div class="title"> Sidebar content</div>
    <div class="sub-title">
        Click the button to close the Sidebar.
    </div>
    <div class="center-align">
        <!-- Button element declaration -->
        @Html.EJS().Button("close").Content("CloseSidebar").Render()
    </div>
</div>).Render();
}
<!-- end of sidebar element -->
<div id="head">
    <!-- Button element declaration -->
    @Html.EJS().Button("toggle").Content("Open").IsToggle(true).CssClass("e-info").IconCss("e-icons burg-icon").Render()
</div>
<!-- main content declaration -->
<div class="maincontent" style="height:335px;border:1px solid gray">
    <div>
        <div class="title">Main content</div>
        <div class="sub-title"> content goes here.</div>
    </div>
</div>

<script type="text/javascript">
    document.addEventListener('DOMContentLoaded', function () {
        // create a instances for sidebar element
        var defaultSidebar = document.getElementById("default-sidebar").ej2_instances[0];
        // Show and Hide the sidebar
        document.getElementById('toggle').onclick = function () {
            var togglebtn = document.getElementById("toggle").ej2_instances[0];
            if (document.getElementById('toggle').classList.contains('e-active')) {
                togglebtn.content = 'Close';
                defaultSidebar.show();
            } else {
                togglebtn.content = 'Open';
                defaultSidebar.hide();
            }
        }
        // Close the sidebar
        document.getElementById('close').onclick = function () {
            var togglebtn = document.getElementById("toggle").ej2_instances[0];
            defaultSidebar.hide();
            document.getElementById('toggle').classList.remove('e-active');
            togglebtn.content = 'Open'
        }

    });
</script>
<style>
    /* sample level styles  */    
    .center-align {
        text-align: center;
        padding: 20px;
    }

    #head {
        border: 1px solid #424242;
        border-bottom-color: transparent;
        background: #00897B;
    }

    body {
        margin: 0;
    }

    /* main content styles  */    

    .title {
        text-align: center;
        font-size: 20px;
        padding: 15px;
    }

    .sub-title {
        text-align: center;
        font-size: 16px;
        padding: 10px;
        display: flex;
        justify-content: center;
    }

    /* icon styles  */   
    .burg-icon:before {
        content: '\e10d';
        font-size: 16px;
    }

    /* Button styles  */   

    #toggle, #toggle:hover, #toggle:focus { /* csslint allow: adjoining-classes*/
        background: #00695C;
        box-shadow: none;
        border-radius: 0;
        height: 39px;
        width: 100px;
    }

    #close, #close:hover, #close:active, #close:focus { /* csslint allow: adjoining-classes*/
        background: #fafafa;
        color: black
    }

    /* Sidebar styles  */  

    #default-sidebar {
        background-color: #26A69A;
        color: #ffffff;
    }

    /* custom generated icons styles */
    @@font-face {
        font-family: 'e-icons';
        src: url(data:application/x-font-ttf;charset=utf-8;base64,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) format('truetype');
        font-weight: normal;
        font-style: normal;
    }
</style>

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc;

namespace WebApplication.Controllers
{
    public partial class SidebarController : Controller
    {
        public IActionResult context()
        {
            return View();
        }
    }
}