Add meta property position to my breadcrumbnav

support
1

hello,
Using Breadcrumb Navigation on my site, but I want to add a meta property position to my breadcrumbnav. like this

<ol vocab="https://schema.org/" typeof="BreadcrumbList">
      <li property="itemListElement" typeof="ListItem">
        <a property="item" typeof="WebPage"
            href="https://example.com/books">
          <span property="name">Books</span></a>
        <meta property="position" content="1">
      </li>
      ›
      <li property="itemListElement" typeof="ListItem">
        <a property="item" typeof="WebPage"
            href="https://example.com/books/sciencefiction">
          <span property="name">Science Fiction</span></a>
        <meta property="position" content="2">
      </li>
      ›
      <li property="itemListElement" typeof="ListItem">
        <span property="name">Award Winners</span>
        <meta property="position" content="3">
      </li>
    </ol>