Why this plugin not working s

Fatal error: Uncaught exception ‘Recurly_ConnectionError’ with message ‘Failed to connect to Recurly.’ in /home/stockato/public_html/wp-content/plugins/recurly-plans/lib/recurly/client.php:185 Stack trace: #0 /home/stockato/public_html/wp-content/plugins/recurly-plans/lib/recurly/client.php(151): Recurly_Client->_raiseCurlError(6, ‘Couldn’t resolv…’) #1 /home/stockato/public_html/wp-content/plugins/recurly-plans/lib/recurly/client.php(79): Recurly_Client->_sendRequest(‘GET’, ‘/plans’, NULL) #2 /home/stockato/public_html/wp-content/plugins/recurly-plans/lib/recurly/pager.php(124): Recurly_Client->request(‘GET’, ‘/plans’) #3 /home/stockato/public_html/wp-content/plugins/recurly-plans/lib/recurly/plan_list.php(19): Recurly_Pager->_loadFromXML(‘/plans’, NULL) #4 /home/stockato/public_html/wp-content/plugins/recurly-plans/recurly.php(150): Recurly_PlanList->getPlanXML() #5 /home/stockato/public_html/wp-content/plugins/recurly-plans/recurly.php(129): get_plans(‘momths’, ”) #6 [internal function]: plans_shortcode(Array, ”, ‘ in /home/stockato/public_html/wp-content/plugins/recurly-plans/lib/recurly/client.php on line 185

trying to impleneting and show all recurly plans on wp based sites giving above error

Please help me

https://wordpress.org/plugins/recurly-plans/