open graph markup

I am trying to get an open graph image on sites when I cut and past a URL to them, this is the code i Have

I have tried to put it in the APP HTML header, and as a page source (before content)

None seem to work, has anyone got this working?

(yes its a https site)

You can’t put an html tag in either of those locations. The browser will just ignore it because the web framework already returns one.

Not what I said. You just can’t put it in html header or a page source object the way you indicated.

You may be able to set the prefix attribute on the html element using JavaScript or just serve the entire page using HandleUrl or HandleSpecialUrl.