How to set up Pinterest?

I have the Pro plan of “WP to Buffer Pro” and “Buffer”.

All my posts are sent to the Buffer queue except to my Pinterest account. I guest there must be some problem with the format:

Post: {title}
Author: {author_display_name}
View post: {url}

Should I add more information?

Manual publications require: photo, description and source url. I think the source url is the problem. How to solve it?

Thank you very much!