1. Go to the games directory. (Usually in C:\Program Files (x86)\Origin Games\Apex\cfg)
2. Create there a new file called "autoexec.cfg" (without the Quotation marks)
3. Paste everything from autoexec in it.
4. Rightclick on the game inside of Origin and go to "Game Properties".
5. Switch to the "Advanced Launch Options" Tab.
6. Add the Command line argument "+exec autoexec.cfg" (without the Quotation marks)

1. Press Win+R while you are on your desktop.
2. Paste this inside the Run box: "%USERPROFILE%\Saved Games\Respawn\Apex\local" (without the Quotation marks)
3. Open up the Videoconfig.txt with Wordpad or Notepad++.
4. Replace everything in it with the code from videoconfig
5. Save and make the file read-only. (also make sure your Origin Cloud Sync is disabled in the origin settings)

Use RTSS for framerate caping over build-in game engines caps. RTSS is the best in frametime consistancy.

Do not use a higher cap value than 190 FPS since the game will introduce stutter (its a apex bug)

You can download RTSS here