How to get a project going on the Nucleo H745ZI?

Good day everyone,

When I received the Nucleo H745ZI it had the blinking LED program on it. This was working fine.

Now I'm trying to upload my own program and it's not doing anything at all. Both the LEDs and UART aren't giving output. This is after generating a fresh project in CubeMXIDE. Everything default.

My code;

 HAL_GPIO_TogglePin (GPIOB, GPIO_PIN_14);
	 HAL_Delay(50);
	 HAL_GPIO_TogglePin (GPIOE, GPIO_PIN_1);
	 HAL_Delay(100);
	 HAL_GPIO_TogglePin (GPIOB, GPIO_PIN_0);
	 HAL_Delay(200);
 
	 uint8_t buff[4] = {3, 4, 5, 6};
	 HAL_UART_Transmit(&huart3, buff, sizeof(buff), HAL_MAX_DELAY);

I've tried both building and manually uploading the CM7.bin file and using the debug tool in the CubeMXIDE. Both not working.

Firmware has been updated.

By the way, does anyone know where I can find this default program?