og:image without featured image

I have a tricky use case where posts dont actually contain a featured image and cannot. Previously I hooked into the wpseo globals like this to pass an image url to Yoast.

$GLOBALS['wpseo_og']->image_output(IMAGEURLHERE);

Once I did that, Yoast was able to add the og:image meta tags. I cant find a way to do this with the new Yoast API. Any code examples that could help me out?