According to Google, you should add a markup data in order to include your site name in the search results:
In their example of Microdata usage, they attach the website name to the page title
:
<head itemscope itemtype="http://schema.org/WebSite">
<title itemprop='name'>Your WebSite Name</title>
<link rel="canonical" href="https://example.com/" itemprop="url">
But obviously page titles are not the same as website name!
What am I missing here?