Hi,
I'm Rodrigo and I'll help you.
Fn + W command to swap WASD with arrow keys is for specific keyboards that have this feature.
There are many options you can use to swap the keys in the system, one of them is using PowerToys, install it from the Microsoft Store:
https://apps.microsoft.com/store/detail/XP89DCG...
After installing it, open it > Keyboard Manager > Remap a key > Under "Select press select and press the key you want to remap > Under "To send" press Select and press the key you want the remapped key to send.
Press "Add key remapping" to remap a new key and repeat the process with the other keys. > OK to save.
You can turn on/off Keyboard Manager to easily switch between the swaps