How To Integrate SMS API To my ASP.Net Web application

I have a code send from my sms providers it looks like this

var client = new RestClient("https://api.infobip.com/sms/1/text/multi");
var request = new RestRequest(Method.POST);
request.AddHeader("accept", "application/json");
request.AddHeader("content-type", "application/json");
request.AddHeader("authorization", "Basic QWxhZGRpbjpvcGVuIHNlc2FtZQ==");
request.AddParameter("application/json", "{\"messages\":[{\"from\":\"InfoSMS\", \"to\":[\"41793026727\", \"41793026731\"], \"text\":\"May the Force be with you!\"}, {\"from\":\"41793026700\", \"to\":\"41793026785\", \"text\":\"A long time ago, in a galaxy far, far away... It is a period of civil war. Rebel spaceships, striking from a hidden base, have won their first victory against the evil Galactic Empire.\"}]}", ParameterType.RequestBody);
IRestResponse response = client.Execute(request);

I need to integrate this to my asp.net web application