Include code from jQuery load() onto page source code [duplicate]

I am currently using the below to include a header and a footer on every page.

<script src="/js/jquery.min.js"></script>
<script>
    $(function () {
        $("#header").load("https://example.com/modules/header.html");
        $("#footer").load("https://example.com/modules/footer.html");
    });
</script>

The problem is the code on header and footer isn't being included in the source code of the page, so text crawlers like Textise can't see the header or footer content.

How can I push the code of header and footer to be included in the loaded pages' source code?