How to test On Localhost(Virtual host)

Hi,

I have setup virtualhost on localhost. And I have correctly installed plugin as well.
Then I have got following error

Warning: file_get_contents(https://www.linkedin.com/grp/post/g-5010991-S-5844056557532246018): failed to open stream: HTTP request failed! HTTP/1.0 400 Bad Request in C:\wamp\www\freesource\wp-content\plugins\rdp-ingroups\bl\simple_html_dom.php on line 76

So how I resolve this

https://www.ads-software.com/plugins/rdp-ingroups/