I don’t know of anyone using the Ableton Push hardware, version 1 through 3 with Zynthian. The “9” is the software version. Maybe someone else will append who does use it.
If not, you could make it work in a basic way with the midi learn capability in Zynthian.
To really take advantage of the incredible hardware in a powerful way you’d have to write what we call a “driver” for it - this isn’t the same as the “driver” as most people would use the word (low level) and doesn’t require writing in C or C++ but it requires some Python.