The *.html example assumes you have integrated the tracking code as an iframe in the instant articles feed.
<figure class="op-tracker">
<iframe src="https://www.example.com/fia-google-analytics-tracking.html"></iframe>
</figure>
The inline example would look similar to
<html lang="de-ch" prefix="op: http://media.facebook.com/op#">
<head>
<meta charset="utf-8">
<title>Hello World</title>
<link rel="canonical" href="http://example.com">
<meta property="op:markup_version" content="v1.0">
<meta property="fb:use_automatic_ad_placement" content="true">
</head>
<body>
<article itemscope itemtype="http://schema.org/Article">
<header>
<h1>Hello World</h1>
<time class="op-published" datetime="2019-01-08T15:38:14+01:00">8.1.2019 um 15:38 Uhr</time><time class="op-modified" datetime="2019-01-09T14:08:03+01:00">9.1.2019 um 14:08 Uhr</time>
</header>
<div class="article-body">
<div class="copy">
<p>Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet. Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet.</p>
</div>
</div>
<footer>
<small>© Copyright 2010 – 2019, Example.com</small>
</footer>
<figure class="og-tracker">
<iframe>
<!-- see inline-fia-google-analytics-tracking.html -->
</iframe>
</figure>
</article>
</body>
</html>
It categories the traffic coming from FIA in the Social category and also attributes it to the correct network.