Can't find correct board

Hello, new to the forums, so sorry if this is formatted incorrectly.

I am using this control board to control a 2 axis gimbal for a multicopter. However, I can't seem to find the correct board while flashing the firmware to it, so I can't even move on with the project. I have installed all the official Arduino boards through the Board Manager, and found a few new boards that I added to the boards.txt file, but I can't seem to find the correct one. All I know about the board is that it uses the ATMega328P processor, but all of the boards I tried with that one failed.

The error that I got when using a board I saw used in tutorials is this:

In file included from I2Cdev.h:74:0,
from I2Cdev.cpp:44:
C:\Program Files (x86)\Arduino\hardware\arduino\avr\cores\arduino/Arduino.h:249:26: fatal error: pins_arduino.h: No such file or directory
#include "pins_arduino.h"
^
compilation terminated.
Error compiling.

I feel like I'm missing something easy, but I don't know what else to try. Thanks in advance.

You can find lots of helpful documentation here: brushless-gimbal-BruGi download | SourceForge.net