Fix Error: (#100) Only owners of the URL have the ability to specify the picture, name, thumbnail or description params.

This error occurs when your website is not authorized to post to the Facebook page, this is due to security procedures put in place by Facebook to prevent unauthorized posts from external sources to be shared to your Facebook page. 

To fix this please have a look at this document from Facebook: https://developers.facebook.com/docs/sharing/domain-verification

Once you've gone through the verification process, the change might not be immediate, so please have some patience, if a few hours has passed and you're still receiving the error, then try disconnecting your Facebook account from the ROP dashboard and re-adding it and test sharing again.