StupidassEASpamDetectionisbrokencrap

Create another Windows account then the game profile will be a per windows user setting as the key configs are saved in

%userprofile%\Saved Games\Respawn\Apex\local\settings.cfg

your other option is to have a batch file or powershell script which will copy a backup of the settings.cfg to the profile location
you can have it with menu launch for yourself and for your brother it copies the keyconfig in place on launch.

setup the keys how you like them save exit the game copy

%userprofile%\Saved Games\Respawn\Apex\local\settings.cfg

to a folder / Directory call it mine.cfg have your brother set his keys up in game save and then copy

%userprofile%\Saved Games\Respawn\Apex\local\settings.cfg

have him call it bros.cfg

Put the folder anywhere on your machine copy the apex legends shortcut into the folder you should have 4 files inside it after creating the Profileswitcher.bat which is tacked on to the end here.
...
Apex Legends.lnk
bros.cfg
mine.cfg
ProfileSwitcher.bat
....

Create a txt file called profileswitcher change the extension to .bat
After this copy text after : into your profileswitcher.bat
:::


ECHO OFF
CLS
:MENU
ECHO.
ECHO _________________________
ECHO PRESS 1, 2 OR 3 to EXIT.
ECHO _________________________
ECHO.
ECHO 1 - My Profile Launch Apex
ECHO 2 - Brothers Profile Launch Apex
ECHO 3 - EXIT
ECHO.
SET /P M=Type 1, 2, 3, press ENTER:
IF %M%==1 GOTO mine
IF %M%==2 GOTO bros
IF %M%==3 GOTO exit
:mine
echo %CD%
copy %CD%\mine.cfg "%userprofile%\Saved Games\Respawn\Apex\local\settings.cfg"
start %CD%\"Apex Legends.lnk"
GOTO EOF
:bros
copy %CD%\bros.cfg "%userprofile%\Saved Games\Respawn\Apex\local\settings.cfg"
start %CD%\"Apex Legends.lnk"
:EOF
EXIT