Please find code here :-

<template id="inherit_header_website" inherit_id="website.template_header_default">
<xpath expr="//t[@t-call='portal.user_dropdown']" position="before">
<li>
<t t-call="website.website_search_box_input">
<t t-set="_form_classes" t-valuef="o_wsale_products_searchbar_form o_not_editable p-2"/>
<t t-set="_classes" t-valuef=" "/>
<t t-set="search_type" t-valuef="search_type"/>
# For example: <t t-set="search_type" t-valuef="products"/>
<t t-set="action" t-value="'action url which values should be search'"/>
# For example: <t t-set="action" t-value="'/shop'"/>
</t>
</li>
</xpath>
</template>