why assets’s JS files functionality not add in my NEXTJS projects

i just use any other html template and i want to use that template in my nextJS admin template so i just convert my html code in JSX and add assets folder in my nextJS public directory all asset’s CSS code successfully render on browser but also assets JS file render in browser but template no any functionality add in my theme while when i run my HTML template with only assets then that is easily run with whole JS functionality .

import localFont from "next/font/local";
import "./globals.css";

const geistSans = localFont({
  src: "./fonts/GeistVF.woff",
  variable: "--font-geist-sans",
  weight: "100 900",
});

const geistMono = localFont({
  src: "./fonts/GeistMonoVF.woff",
  variable: "--font-geist-mono",
  weight: "100 900",
});

export const metadata = {
  title: `Metronic - the world's #1 selling Bootstrap Admin Theme Ecosystem for HTML, Vue, React, Angular & Laravel
          by Keenthemes`,
  description: "Generated by create next app",
};

export default function RootLayout({ children }) {
  return (
    <html lang="en">
      <head>
        <meta charSet="utf-8" />
        <meta name="description"
          content="The most advanced Bootstrap Admin Theme on Themeforest trusted by 94,000 beginners and professionals. Multi-demo, Dark Mode, RTL support and complete React, Angular, Vue &amp; Laravel versions. Grab your copy now and get life-time updates for free." />
        <meta name="keywords"
          content="Metronic, bootstrap, bootstrap 5, Angular, VueJs, React, Laravel, admin themes, web design, figma, web development, free templates, free admin themes, bootstrap theme, bootstrap template, bootstrap dashboard, bootstrap dak mode, bootstrap button, bootstrap datepicker, bootstrap timepicker, fullcalendar, datatables, flaticon" />
        <meta name="viewport" content="width=device-width, initial-scale=1" />
        <meta property="og:locale" content="en_US" />
        <meta property="og:type" content="article" />
        <meta property="og:title"
          content="Metronic - Bootstrap 5 HTML, VueJS, React, Angular &amp; Laravel Admin Dashboard Theme" />
        <meta property="og:url" content="https://keenthemes.com/metronic" />
        <meta property="og:site_name" content="Keenthemes | Metronic" />
        <link rel="canonical" href="https://preview.keenthemes.com/metronic8" />
        <link rel="shortcut icon" href="assets/media/logos/favicon.ico" />
        <link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Poppins:300,400,500,600,700" />
        <link href="assets/plugins/custom/fullcalendar/fullcalendar.bundle.css" rel="stylesheet" type="text/css" />
        <link href="assets/plugins/custom/datatables/datatables.bundle.css" rel="stylesheet" type="text/css" />
        <link href="assets/plugins/global/plugins.bundle.css" rel="stylesheet" type="text/css" />
        <link href="assets/css/style.bundle.css" rel="stylesheet" type="text/css" />
      </head>
      <body
        className={`${geistSans.variable} ${geistMono.variable} antialiased home blog wp-custom-logo dark-background dark-version main-layout-boxed disable-floating-video header-vid-default beeteam368 elementor-default elementor-kit-12 header-fixed header-tablet-and-mobile-fixed toolbar-enabled toolbar-fixed aside-enabled aside-fixed`}
        id="kt_body"
        style={{ height: 'var(--kt-toolbar-height)' }}
      >
        {children}

        <script src="assets/plugins/custom/fullcalendar/fullcalendar.bundle.js"></script>
        <script src="assets/plugins/custom/datatables/datatables.bundle.js"></script>
        <script src="assets/js/widgets.bundle.js"></script>
        <script src="assets/js/custom/widgets.js"></script>
        <script src="assets/js/custom/apps/chat/chat.js"></script>
        <script src="assets/js/custom/utilities/modals/upgrade-plan.js"></script>
        <script src="assets/js/custom/utilities/modals/create-app.js"></script>
        <script src="assets/js/custom/utilities/modals/users-search.js"></script>
      </body>
    </html>
  );
}

Image of all assets folder

i try to use a ready made HTML template with his all functionlity in NEXTJS.