For piano playing, this is a nice format:
https://shop.boox.com/products/boox-blue-page-pedal
I don't own one and nobody has yet reported exactly what keystrokes it sends. It's not clear what/how many modes there are. There does not seem to be any documentation online. The boox.com website has it, but it directs you to the US website which doesn't have it.
[1st photo]
There is also the iRig stuff, with two or four buttons.
https://www.ikmultimedia.com/products/irigblueboard/
https://www.ikmultimedia.com/products/irigblueturn/
They say that now the two buttons supports native PgUp/PgDn compatible with Android. The four button used to (and apparently still) only supports Apple and used an interface app.
I kind of like the format of the four button and wrote my own Android app for it. That was a bit of a pain because you had to start that app. So I ripped out the circuit board and made my own that natively sent keystrokes without needing a helper app.
[2nd photo]
There are also many "guitar style" footboards but they also use those metal stud switches.
If you want to use wired USB the Infinity is a good quality, three pedal stenographer unit. You'd need a helper app to make it spit out keys.
Finally, with Onyx there is the whole quagmire of the long press and whether things react on the press or the release. I hacked stuff to defeat that so that action occurs on the downstroke.