we need the list datatype as Return List,

codeunit 50001 TestCodeunit
{
procedure TestingFunctionList()
var
String : Text;
begin
ListString := SplitingStringtoList(String);
end;

local procedure SplitingStringtoList(String: Text) : List of [Text]
begin
Exit(String.Split(','));
end;
}
we don't want to write String.split every time, if return accepts then it will easy and Re-Usable.

Same As Split Function is returning the variable.

thanks!