🚀 go-pugleaf

My procedure is as below:
CREATE OR REPLACE PROCEDURE BillLogin(
    sProvider OUT Admins.provider_no %TYPE)
AS
BEGIN
    SELECT provider_no
    INTO sProvider
    FROM Admins
    WHERE admin_id = 'test'
END;

I'm sure the result is one row only

My codes are as below:
if(!ADOConnection1->Connected)
{
    this->ADOConnection1->Open();
}
ADOStoredProc1->ProcedureName = "BillLogin";

ADOStoredProc1->Parameters->Clear();
ADOStoredProc1->Parameters->AddParameter();
ADOStoredProc1->Parameters->Items[0]->DataType = ftString;
ADOStoredProc1->Parameters->Items[0]->Direction = pdOutput;
ADOStoredProc1->Parameters->Items[0]->Name = "sProvider";

ADOStoredProc1->ExecProc();
Edit1->Text = VarToStr(ADOStoredProc1->Parameters->Items[0]->Value);


When I run the exe file, I receive error message:
"Parameter object is defined incorrectly. Inconsistant or incompleted
information is provided."


Can anyone tell me how to set patameters for TADOStoredProc?