The easiest would be to add our search widget in WordPress ==> Appearance ==> Widgets.
Generally speaking our service will work with any input box on the site. So adding html like the following into your php header theme file should do the trick:
<form class="isp_search_box_form" name="isp_search_box" action="/" style="width:10rem;">
<input type="text" name="s" class="isp_search_box_input" placeholder="Search..." autocorrect="off" style="outline: none; width:10rem; height:2.1rem;">
<input type="hidden" name="post_type" value="product">
<input type="image" src="/wp-content/plugins/instantsearch-for-woocommerce/widget/assets/images/magnifying_glass.png" class="isp_widget_btn" value="">
</form>
Also, since every theme might be slightly different, it’s hard to help out without the specific site URL. Please contact our support@instantsearchplus.com for further assistance with your site URL.
Best,