og:image in sabai listing

Hi there,

I use your great plugin but I have a problem with og:image in my sabai plugin listing – even as I have a nice pic on my listing it is not listed:
http://www.via-ferrata.de/klettersteige/topo/sentiero-scaloni-sentiero-anglone
can you have a look at it please and tell what I have to do in order to get this og:image listed. when I use facebook debugger I get the message:
The ‘og:image’ property should be explicitly provided, even if a value can be inferred from other tags.
I already tried almost all settings under “Social Meta” and “IMage Settings” OG:select Image source
can you help me and tell me how I can get the image with the ladder get listed as og:image?!

https://wordpress.org/plugins/all-in-one-seo-pack/