Plugin not work

Hello,
I installed plugin and by following the instructions I put short code into travel page, You can see this test page at http://7rungi.com/?page_id=6
when I enter information and dates and click on compare it do not work so overall plugin is not working please help out on this issue.

Regards,
Syed

https://wordpress.org/plugins/travel-search/