Radzen calculeted fields

Hi,

In my project I have two fields. One is a number, another one is dropdown with VAT percentage. In add page I have managed when user type number and select percentage of VAT in third row I manged to calculate values. In edit part I have managed to get same result but user must click on dropdown because in change event of this dropdown I have seted property value. First field dosen't see dropdown value.

Wedding_Tax_Percent

${event.Type_tax.replace("%", "")} and I can access this event part only in dropdown not in any other section not in load data or in first field. I save ID not value of dropdown that displays percentage. Could you help me?