Getting Cannot Send the test request error

Hi ,
I am new to Katalon Studio(API testing) . While sending a GET request got below error

From Katalon studio Object repository got the below error.
image
ava.net.SocketException: Unexpected end of file from server
at com.kms.katalon.core.webservice.common.RestfulClient.response(RestfulClient.java:161)
at com.kms.katalon.core.webservice.common.RestfulClient.sendRequest(RestfulClient.java:86)
at com.kms.katalon.core.webservice.common.RestfulClient.send(RestfulClient.java:49)
at com.kms.katalon.controller.WebServiceController.sendRequest(WebServiceController.java:107)
at com.kms.katalon.composer.webservice.parts.RestServicePart$6.run(RestServicePart.java:189)
at org.eclipse.jface.operation.ModalContext$ModalContextThread.run(ModalContext.java:119)

Please not the server is not responding , from postman got this error " Could not get any response There was an error connecting to [http://xxx.xxx.xxx/xxx]"

Kindly suggest.