PowerApp Sort function

Hi Guys,

I'm struggling with a sort button. I would like to sort on the date of the browse gallery. The oldest records must be on top instead of the bottom. Can someone help me?

I have tried these syntaxes with no result:

• SortByColumns([@'Declaraties Etesian'];Text("ThisItem.Datum";"[$-en-US]mmddyyyy"); Descending
• SortByColumns([@'Declaraties Etesian'];Text("Thisitem.datum";"[$-nl-NL]Today()"); Descending)
• SortByColumns([@'Declaraties Etesian'];Text(“DataCardValue2";"[$-en-US]mmddyyyy"); Descending)
• SortByColumns([@'Declaraties Etesian'];Text("DataCardValue2";"[$-nl-NL]Today()"); Descending)
• SortByColumns([@'Declaraties Etesian'];Text("Body1";"[$-en-US]mmddyyyy"); Descending)
• SortByColumns([@'Declaraties Etesian'];Text("Body1";"[$-nl-NL]Today()") ; Descending

• SortByColumns([@'Declaraties Etesian'];Text("Created";"[$-en-US]mmddyyyy");Descending)