Is it possible to do this with the Add HTML app? If so, how can I do it?

Hi everyone.

I was hoping you could help me with this one. I have this page where I can’t change the HTML directly, but the Head section contains the following text (obviously, the > was removed here, or this wouldn’t work in the forum):

<title MY TITLE HERE</title
<meta name="description" content=""
<meta property="og:description" content="SOME TEXT HERE" /

Is it possible, perhaps using the Add HTML app, to get the content of the “og:description” property and add it as the meta description? And, if so, how can I do? My intent is specifying a Meta Description for all pages, but I cannot do it directly, since I cannot edit the code of the page as one would normally do.