Where is the fuse for the horn and what is the number? Thank you

The schematic does use numbers. sure but there is NONE.
why not ask how to diagnose it and not guess?
here ill look at alldata.com (so can you)
prior to about 2007, there was a horn fuse, not now.

OPEN hood, see that TIPM box, with zillions of fuses and relays.
BINGO. its all there on one box, thus its name .

it also is a slave computer to the can-bus masters .
Ill quote the FSM now.
"to diagnose the horn system requires the use of a scan tool"
do you know why?
ill explain, the button is pressed, the Cluster brain sees that and sends
a command (serial CAN-bus data) to TIPM box, it receives, it
and activates the horn driver module (be that a relay or transistor)
and the horn honks. (that module has no socket)

if you get COMM errors, then the horn can fail
even with all horn parts good end to end.!!!!
see? all that magic, with distributed processing?
Allen Turning with be shocked. (or eat his apple, RIP)

bad news, the horn relay is soldered into the TIPM
that cant stop me , I have a pro soldering station. (since 1975)

DTCs (scans)
U0141?

all this fancy junk started in 2007 , making scan tools mandatory

ok took, me awhile to find your answer, (due to blurry schematics online)
there is NO HORN FUSE, so your ASSUMPTION is wrong.
the TIPM fuse main power is ALL, to IT, is all the power it needs
to drive the horn and other things, and that is not blown because the TIPM goes dead
and with that vast other things, bringing us full circle back to square 1.

why not scan it first, like your ASE pro will do, step one.