Social Content Crawler - posttofacebook() - Images are not getting posted.

Hi,

I am using Social Content Crawler plug-in to publish the post in FB page with Appian Version 18.1. 

By use of posttofacebook(post, pictureUrl, name, caption, description, postUpdateAsLink, thirdPartyCredentialsKeyList), able to publish the post in FB page.

But Images are not getting posted.

Written code like below, but its not happened 

posttofacebook(
post: "Hi",
pictureUrl: "thumbs.dreamstime.com/.../tiger-portrait-horizontal-11392212.jpg",
name: "name",
caption: "caption",
description: "description"
)

Can any one have any idea about this.

Regards,

Pavan Kumar Challa