I've had a few Aveox controllers over the years. I haven't programmed one in quite a while but I believe it involved holding the button down for 5 seconds or something. That taught it neutral point, then go full throttle and push the button, then full brake and push the button again. You may have to go back to neutral and push the button one more time, I just can't remember. I do know someone that has the printed instructions though so I'll see if I can take a look next time I see the person. You can also enable/disable reverse and turn the low voltage cutoff on/off. One of them is holding the button down while plugging power in and then releasing the button a second later. The other is holding it down while plugging power in but you need to keep holding it down for more then 5 seconds.
Let me know if you you're still having problems, I'll see what I can dig up.