Hi,
there should not be an issue to make communication between those boards. You should keep following...
- use 12V power supply to power both boards to enable SBC's CAN transceiver
- boards are connected using 3 wires (CANH, CANL, GND)
- DEVKIT_MCP5748G does not have termination resistor, so it could be needed in case of communication issues
- the same bitrate including sample point must be set on both MCUs
- check if both MCU use the same CAN FD protocol, is configurable by CTRL2[ISOCANFDEN] bit
BR, Petr