We apologize for the long delay in response.
The Link Post Format does not function as a link to external site in a page built in WP Show Post. It sends to a (internal) regular Post. Any way to fix that? Thanks.
Not sure I understand what you mean. WP Show posts doesn’t build pages. As it is a blog list plugin, it only displays a post list loop. It doesn’t make one.
As for the “link”, if you mean the read more button, it’s for sending the site visitors to the full post of the post associated to it.
Code can be found here as to how it functions: https://github.com/tomusborne/wp-show-posts/blob/35e410d7800273fc66f211c0f80d553e95d17f83/inc/functions.php#L231
If perhaps you meant the link within the entry content, these links depend on what you set them within the content of the post associated to them.
On the same github link, you’ll find that WPSP plainly displays the content, not alter it.