DFU update for nrf51422 multirole lesc


I am using sdk11 and nrf51422 device with s130 softdevice for ble_multilink_lesc example code. How do I add DFU service in the existing code? I have added DFU service for other peripheral examples. But here when I follow the same procedure, the device is not at all advertising(not seen in nrf connect mobile app).