[otrs] curl: (52) Empty reply from server was displayed when Run curl command for REST Requests

Dear all, I want to get ticket ditail using curl command for REST interface. So that, I refered to the following URL. Reference page: https://otrs.github.io/doc/manual/admin/stable/en/html/genericinterface.html... * cURL Examples for REST Requests Run curl comand on otrs server, but error message was displayed on console. Error message is "curl: (52) Empty reply from server". otrs version: otrs-4.0.7-01 OS: CentOS 6.6 Run command # curl "http://127.0.0.1/otrs/nph-genericinterface.pl/Webservice/GenericTicketConnec..." * xxx= replace value of my environment Is the curl command option wrong ? Please tell me, How to get ticket ditail using curl command. Sincerely, katsuji