why fnCellRender doesn't work in my project

innatriosoft

Hello,I try to use fnCellRender even example from your api doesn't work
from https://datatables.net/extensions/tabletools/button_options

"fnCellRender": function ( sValue, iColumn, nTr, iDataIndex ) {
// Append the text 'TableTools' to column 5
if ( iColumn === 5 ) {
return sValue +" TableTools";
}
return sValue;
}

Thanks a lot