Открываем терминал и проверяем нажатие клавиш

xev -bw pixels

"Колесико мыши влево"
ButtonRelease event, serial 37, synthetic NO, window 0x5000001,
root 0x167, subw 0x0, time 20701898, (105,45), root:(1434,514),
state 0x10, button 6, same_screen YES

"Колесико мыши вправо"
ButtonRelease event, serial 37, synthetic NO, window 0x5000001,
root 0x167, subw 0x0, time 20697890, (107,45), root:(1436,514),
state 0x10, button 7, same_screen YES