Configuring inputs for PCSX-ReArmed and NES30Pro

[JohnRudy]

Hi there.

I have a RaspberryPi Zero W with the latest RetroPie installed and it's housed inside a Retroflag GPi case. Works like a charm. Will be a permanent housing solution for this.
I noticed that the PCSX-ReArmed (not the "ls" one) emulator that is in the optional packages can run some PSX games on it. I've installed it through binary and the next step is to get the controller mapped.
Following the guide in the docs I'm now at this point

PCSX-ReARMed Controls

PCSX-ReARMed controls and configurations are located in

/opt/retropie/configs/psx/pcsx.cfg

I've located the folder but that .cfg does not exist.

pi@retropie:/opt/retropie/configs/psx $ /opt/retropie/configs/psx/pcsx.cfg
-bash: /opt/retropie/configs/psx/pcsx.cfg: No such file or directory

Anyone who owns the RetroFlag case knows that the OTG usb cord that comes with the RaspberryPi Zero is too big for the small battery compartment USB port so I would need to configure the config to get the buttons working. Meaning I can't get my wireless keyboard connected for now.
Using putty for now to connect through SSH and FileZilla to move stuff across.
I'm using this older 8BITDO NES30Pro controller that I'd like to set up so that it would work with the emulator, seeing as how the buttons on the actual case don't work on the emulator (for whatever reason).
I've done JSTest and noted down each button and axise for the controller.

Here comes the question. Do I just create that cfg file or is the documentation old and there is a newer way of mapping the controller to work? I honestly probably just need the hotkey to work so I can map them inside the arch menu.

Thank you in advance, any and all help is appreciated.

EDIT: I've all ready tested with Crash Bandicoot and the emulation to the menu at least is flawless, just cant navigate.
EDIT 2: Just fixed some typos.

[JohnRudy]

Ok so in the end I did have to brutalize a little the battery compartment. Whittled away a little of the plastic around the usb connector in the back to get my OTG cable to fit. Got the keyboard working and now the cfg was created finally. Now I just have the basic problem of controls not working as expected. Seeing as how the NES30pro controller uses the the d-pad buttons as axis controls and not as legitimate buttons, i need to get the axises to the cfg the right way.

I've seen people just switching to a Dualshock type in the controls menu but I'm missing this option as well. The troubles never end.