allowfullscreen

Default behavior

HTML

<o-embed url="https://www.youtube.com/watch?v=G_QhTdzWBJk"></o-embed>

No Full Screen

HTML (variant 1)

<o-embed
  url="https://www.youtube.com/watch?v=G_QhTdzWBJk"
  allowfullscreen="false"
></o-embed>

HTML (variant 2)

<o-embed
  url="https://www.youtube.com/watch?v=G_QhTdzWBJk"
  allowfullscreen="0"
></o-embed>