If the button already has a function (like back) assigned to it, I think the input-remapper[0] software would work. That is what I use with my deathadder. [0]

If the button already has a function (like back) assigned to it, I think the input-remapper[0] software would work. That is what I use with my deathadder. [0] https://github.com/sezanzeb/input-remapper https://github.com/sezanzeb/input-remapper