wwv_flow.g_f01.count not working in apex5 oracle

I am ruing below piece of code on button click but nothing is inserted in dummy_tbl table.

   DECLARE
    vRowNumber number;
    BEGIN
     FOR ii IN 1..wwv_flow.g_f01.count LOOP
    vRowNumber := WWV_Flow.g_f01(ii);
      insert into galaxy_apex.dummy_tbl
      values(vRowNumber);
    END LOOP;
    COMMIT;
    END

The call reached to the pl/sql block when I insert some error in it. what am I doing wrong??