How to call external javascript function in angular 5?

Question

I have downloaded a theme from this link. I have to define script and CSS in index.html file.

index.html (body section)

Answer 1

You can call these methods by window object-

document.addEventListener("DOMContentLoaded", function (event) {
      window['navbarToggleSidebar']();
      window['navActivePage']();
 });