Create a secure soap communication in C#

The Dutch health authorities have a webservice called "grouper". My application is used by health professionals, and they want information from the grouper. My application has to create a request (my responsibility), send the request to the grouper (this assignment), receive answer back (this assigment), and presents the answer to the user (my responsibility). For this assignment I've created a console application with a test message, the assignment is complete when the answer is stored in a variable.