Any fender bender in the past?
Not sure whether the horns are wired up in parallel or series.
But from the description of the issue, the horns aren't receiving power.
It is unlikely that both horns would simultaneously fail so they're likely wired in series.
So the issue is likely either a bad connection at the horn(s), or one of the two in series, has failed.
I had wired up an additional set of horns on the motorcycle.
https://www.r6-forum.com/threads/guide-for-wiring-new-horns.444878/
Though there are a few ways to do it, most horn circuits simply throw 12v at the horn.
To test your circuit, get a circuit tester.
https://www.amazon.com/gp/product/B000EVYGZA/
Connect the negative (black) probe to another ground... which is basically any exposed metal. (will have to scrape off a spot in order to get through the layer of corrosion)
With someone pressing on the horn switch, probe the connections at the horns for 12v.
If you find that the horns are receiving 12v but not activating, try cleaning up the connections.
If they still don't function remove from the vehicle and individually test each horn. (simply apply 12v directly to the horn - wear ear plugs)
If 12v is not reaching the horn, go back to the relay.
Just because the relay 'clicks', doesn't mean it's actually passing on 12v.
The relay should have two thicker wires, and two thinner wires.
The thinner wires will be the coil - operated via the horn switch.
The thicker wires will likely be 12v from the fuse, which then gets passed on to the horns.
Probe the thicker wires with and without the horn switch activated.
If it's clicking but there's no change in your readings, then the relay has failed.
If you are getting 12v at the relay but not at the horn, there is a fault in the wiring between that relay and the horn.
If the relay isn't clicking with the horn switch, then probe the thinner wires to confirm that the coil is either being grounded with minimal resistance, or receiving power that is equal to battery voltage. A weak connection or bad switch can prevent a relay coil from operating as it should.
"Voltage drop testing" is a great tool for isolating weak connections. A straight-in or safety pin can be used to pierce wiring insulation; getting a reading without stripping/damaging/altering the wire. (just be sure not to stab self)