I'm working on a Tampermonkey script to hide related videos on youtube if the og:video:tag contains "League of Legends".
When I use the Open Graph Debugger (link) it find many tags (og:video:url, og:video:width, og:video:tag, ...) but when I search in the DOM I am unable to find any of these elements.
I've tried disabling all my extensions, from a clean profile, from incognito as well as using an Open Graph Extension still I can't find the tags.
Some other attempts:
$('[property="og:type"]') => null.
document.getElementsByTagName('meta') => two unrelated tags.