Printing to fiscal thermal printer issue

Question

I have an project and it support all printer but not the thermal printer(fiscal),In my app i have the option example when u print the receipt u have to choose the printer and the fiscal printer doesnt show there,so ill need to change the code my printer is model : fp 700, my project is a c# project here is my print code

   private void btnPrintReceipt_Click(object sender, EventArgs e)
    {
        parameter.autoprintid = "2";
        POSPrintRpt mkc = new POSPrintRpt(lblReceiptNo.Text);
        mkc.ShowDialog();
}