How can i add / render a single header and footer code to every html file once?

I Want to render single header and footer to every html page
I want header and footer to all of my pages in the website.
Kindly give me the solution to add or render a single header and single footer to every page, so that i don’t need to rewrite paste the code of header and footer again and again on each html file. I need solution with proper code and proper guide Please.
Here is my website name : vortifytech and solution

I used the code below but it’s not working
Kindly provide the solution with code and proper guide.

your text

<script src="https://code.jquery.com/jquery-3.3.1.js"
    integrity="sha256-2Kok7MbOyxpgUVvAk/HJ2jigOSYS2auK4Pfzbm7uH60=" crossorigin="anonymous">
    </script>
<script>
    $(function () {
        $("#header").load("header.html");
        $("#footer").load("footer.html");
    });
</script>