How to insert schema.org microdata attribute?

Question

Joomla

Good afternoon !
I'm trying to insert : itemscope itemtype="http://schema.org/Product"
into the file : templates/bootstrap4/html/com_virtuemart/productdetails/default.php
In theory, I should get:

<div class="product-container productdetails-view productdetails container" itemscope itemtype="http://schema.org/Product">

but in the output on the site the div does not display this option, it turns out :

<div class="product-container productdetails-view productdetails container">

don't tell me why?

Answer 1

No one to advise at all?