Is it possible to insert thumbnail image URL from page properties of Thumbnail tab into og:image inside meta tag. I am able to get values of pageTitle and description properties but not the image. Or is there a better way to handle this?
if the thumbnail image is coming from DAM ,then the page have "image" node in jcr:content of page and that image node will be having fileReference property which will have your image path of thumbnail. In this case you can make use of resource object and get the child node image and then get the property(fileReference).
If the thumbnail has been uploaded from file system in template. In that case it will not be easy to get.i would say take thumbnail from DAM.