Apex using CPU insed of GPU

So by it using the CPU, are you referring it's using the integrated graphics rather than your GPU?
Does this happen with other games or just Apex? Are you using a Laptop or a PC?

If it is indeed using your iGPU / Integrated Graphics, then it's possible to tell your Operating System to use your GPU rather than your Integrated Graphics.

For Windows 10 this can be done:

1. Press Windows Key + R (This should open a Run Dialog)
2. Type in: ms-settings:display-advancedgraphics and press OK
3. Under "Graphics Performance Preference" click on "Browse"
4. Add the r5apex_dx12.exe executable (From the directory your game is stored)
5. Click on the "Options" button
6. Set it on High Performance (Which should be the correct GPU)
7. Click "Save"

Now Windows should make Apex use the correct GPU.
If this doesn't fix your issue, please provide a DxDiag as it will give a bit more information to work with for troubleshooting, steps on how to retrieve a DxDiag can be found in this article: https://help.ea.com/en/help/pc/how-to-gather-dxdiag-information/