You'll need to setup the mouse with the software that came with it.

There's only 5 "standard" buttons on a mouse, every other button has to be configured with extra software to say what key/macro to use (how flexible it is depends on the software/mouse). As you can imagine I've not tested all mice in the world, but in my experience most come "preprogrammed" so that pushing extra buttons is the same as pushing the number keys or the F-keys etc. You can change these defaults with the software.

If you're trying to use it on a PS4 though (you didn't say) it depends if the mouse stores the configuration on the mouse itself (which will work with a PS4, just need to configure it elsewhere) or if it requires the software (in which case you'll be unable to change it from the defaults, if any).

Then in the game from the keybinds menu you modify the keybinds to match whatever keys you set on the mouse software or map the mouse software to match the keybindings already in the game, it doesn't matter which way round.

Hope this is some help!