Value from sql to textbox c#

Question

I need this result display to text box

select SUM(CAST(REPLACE(iznos_sa_pdv,'.', '.')AS decimal(18,2)))
from mp_kasa_lista
WHERE datum >= CONVERT(datetime, convert(varchar(10), GETDATE() ,120), 120) AND datum < DATEADD(day, 1, convert(datetime, convert(varchar(10), getdate(), 120), 120))
  AND tip_placanja='Virman'

 Result is 582,00