HTTP protocols

Question

I’m new to development and I’m learning how to make a web service

below this my method of consultation, insertion and removal. they are already working, however I wanted to know how to pass in the code which method to use.

Att

ex: method consult when "GET" method insert using "POST" Delete method using "DELETE" method update using "PUT"

[WebMethod]
public string ConsultarSensor()
{
   NegSensores regrasSen = new NegSensores();
   List<SEN> colecao = new List<SEN>();
   JavaScriptSerializer jss = new JavaScriptSerializer();

   string jsonSen = string.Empty;

   colecao.AddRange(regrasSen.ConsultarSen(null));
   jsonSen = jss.Serialize(colecao);

   return jsonSen;
}

[WebMethod]
public void InsertSen()
{
   NegSensores regrasSen = new NegSensores();
   regrasSen.InsertSensor("SEN", "Input_20", false, 30, 15, "aaaaaaaaaa", "ouhjflkdfh",1);
}

[WebMethod]
public void DeleteSensor()
{
   NegSensores regrasSen = new NegSensores();
   regrasSen.DeletSen(6);   
}