Unable to change rowId of row of DHTMLX grid


I am using setRowId and changeRowId function to change rowId
of DHTMLX grid.
It is not able to change RowId of row.

Code snippet:

for (var i = 0; i < checkingsGrid.getRowsNum(); i++) {
checkingsGrid.setRowId(i, i+1);


Why it is not working?

It works for me