In @Heinrich-vanNieuwenh’s repo you will find a main.c in CM7/Core/Src.
It was written for a NUCLEO-H745ZI. I don’t know the exact differences with your H743 Nucleo board.
Here is my main()
// Initialize GPIOs for Ethernet here
FreeRTOS_IPInit( ucIPAddress,
ucNetMask,
ucGatewayAddress,
ucDNSServerAddress,
ucMACAddress );
vTaskStartScheduler();
for(;;) {}
Beside calling FreeRTOS_IPInit(), it is very important to set the clocks of the CPU:
/* Configure the system clock */
SystemClock_Config();
Also, as described in the readme.md, you will have to define a RAM section that can be used for DMA.
Here is the latest version of the STM32H7 driver.