Sorry there is no other way to do this but through the software, but you can use either a PC or an Android device to set the mouse acceleration to any level you need. Also remember that there is acceleration of some sort (timed, temporal, etc.) built into most console games, so removing it entirely takes some work and may not be entirely possible depending on the game. Using a custom mouse curve is the best way to counter it depending what you need to do.

For a game like apex, What would I do to counter it?

For Apex there is timed acceleration built into the game that cannot be entirely overcome, but you can use custom mouse curves to mitigate it as much as possible. The aim/look speed of the game isn't too bad overall, so I suggest finding a mouse sensitivity that feels good and allows tracking your shots well while shooting enemies in your field of view, then using a curve to increase the turning speed for enemies behind you. The hardest part is dialing in the curve for turning around. I would start with one of our sample profiles and dial it in for you.

I've attached a couple additional profiles I've been playing with for you to tryout.

I have no access to a computer, but my Rainbow six siege profile sensitive seems to be fine, so I'll just do the direct mapping and remap it to the apex controls for now

Do you have our android app?

im an apple user

I don't have a good solution right now for Apple users, but if you can get to the PC software or Android software to make changes, set in-game acceleration to 35 and KeyMander will have zero acceleration. settings above 35 add an increasing amount of acceleration and below 35 add increasing amounts of deceleration to counteract the acceleration built into some games. I think this maybe the answer you were looking for originally.