What can I do to fix the horn

Did you check voltage at the fuse circuit. Goes hot with the key on. Use voltage tester/testlite. The problem is usually the wiring in the steering column. There are safety issues with working on the steering column because of air-bag. The horn button the steering wheel is a ground for the coil side of horn relay. You could use a jumper wire at the horn relay, relay unplugged, use jumper between terminal 30 and 87, the horn should honk, if terminal 30 is hot.

Hello,

The horn has probably gone bad I would test for power down at the horn itself and then replace it if there is power.

Here is a guide

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

Please let us know what happens.

Cheers, Ken