How to add Site Navigation Schema Markup ?

“Site Navigation Schema Markup” is a bit vague. Are you just trying to mark an element as the SiteNavigationElement?

If there’s a particular guide you’re following it would help if you could share it.

I want to use this markup on my header menu ( categories ). I’m following this guide, https://gist.github.com/gregrickaby/5917114 .
But the code there is pure HTML and mine is with PHP codes. Plzzz help.

According to your header code, your theme appears to use a custom ‘walker’. The walker is how you would modify the output of the menu. Since your theme appears to be a premium/paid theme, you will need to talk to its developers about making modifications.

Thanks but I have got this theme from a fiverr user. I can’t ask him for support.
But I have read this blog about creating a custom walker ( https://elizabethfreemanweb.com/how-to-add-google-structured-data-to-wordpress-menus/ ).

Will you help me to modify my header.php

?? ?? ??