not sure if its the same on the ducati's but when we fit the datatools at work the inline fuse is normally near the battery, sorry i cant be anymore help
If it's any help, my 916 has a fused lead connected to each side of the battery. Failing that, try following all the leads from the alarm unit - mst be somewhere!
if this is a ducati datatool then the fuses are in little rubber fuse holers with rubber covers located witin a few inches of the battery terminals, there is usually one on the pos and another on the negative, when you disconnect thae alarm will go off unless in service mode, even then it might. untill alarm power has drained out cover the noisey unit with a rag or something to muffle the racket. alarm unit usually located under the seat unit secured to the undertray.