How to call a Oracle stored precedure with output parameter in .net 3.1 command type as text?

Question

I have created a following oracle stored procedure to fetch the table data.

CREATE OR REPLACE PROCEDURE GetListOfEmp (
    EMPCURSOR OUT SYS_REFCURSOR
)
AS
Begin
Open EMPCURSOR For
SELECT ID, Name,Value FROM Emp;
End;

Now using c#.net core 3.1 I am trying to execute the stored procedure as below:

> DataSet ds = new DataSet("Datapoints");
>             using (var connection = new OracleConnection("ConnectionString"))
>           {
>              using (OracleCommand cmd = connection.CreateCommand())
>               {
>                   connection.Open();
>                    cmd.CommandText = "var empcur refcursor;Begin GetListOfEmp(:empcur); END;";
>                 cmd.CommandType = CommandType.Text;
>                   OracleDataAdapter da = new OracleDataAdapter(cmd);
>                  OracleCommandBuilder cb = new OracleCommandBuilder(da);
>                da.Fill(ds);
>              }
>           }

In this case getting error as "ORA-00900: invalid SQL statement". But same command text works in the Toad for oracle. Error Message