This one is good and inexpensive. There is also a version with alarm, but the latter is not much apparently. The shipments from China are slow at this moment, though, as few planes fly. Still there might be a US vendor for these.
The original audio suggestions are not that practical. Myself I ride both with a regular bell and an electric horn and apply one or the other, depending what I want to achieve.
Looks interesting. I Googled "Po-ly outdoor products store Bicycle Horn Bike Bell Electric" and couldn't find anything else except on Aliexpress. Nothing about the company "Po-Ly Outdoor Products Store"
There's a few comments about a separate remote controller. Do you really need it? There is a picture with the silicone hanging button. Does it come with the horn?