how to program the option bytes within firmware

[KoSt]

Hello,
After reading the following threads:
How to program STM32 Option Bytes with the HAL API - STMicroelectronics Community
What are option bytes in STM32 and how do I use th... - STMicroelectronics Community
Problem with option bytes set from program level- ... - STMicroelectronics Community
and the manual:
STM32L41xxx/42xxx/43xxx/44xxx/45xxx/46xxx advanced Arm®-based 32-bit MCUs - Reference manual

I tried to stop the watchdog in the STM32G030C8TX under low power MCU modes, by adjusting the option bytes accordingly using the following examples of the HAL library but I get hardware faults. What am I missing?

 

HAL_StatusTypeDef set_OB(void) {

 FLASH_OBProgramInitTypeDef OB;
 HAL_FLASHEx_OBGetConfig(&OB);

 HAL_FLASH_Unlock();
 HAL_FLASH_OB_Unlock();

 OB.OptionType = OPTIONBYTE_USER;
 OB.USERType = OB_USER_IWDG_STOP;
 OB.USERConfig = OB_IWDG_STOP_FREEZE;

 if ( HAL_FLASHEx_OBProgram(&OB) != HAL_OK )
 {
 HAL_FLASH_OB_Lock();
 HAL_FLASH_Lock();
 return HAL_ERROR;
 }

 HAL_FLASH_OB_Launch();

 /* We should not make it past the Launch, so lock
 * flash memory and return an error from function
 */
 HAL_FLASH_OB_Lock();
 HAL_FLASH_Lock();
 return HAL_ERROR;
}

 

 

 

/**
 * @brief The application entry point.
 * @retval int
 */
int main(void)
{
 /* USER CODE BEGIN 1 */

 /* USER CODE END 1 */

 /* MCU Configuration--------------------------------------------------------*/

 /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
 HAL_Init();

 /* USER CODE BEGIN Init */

 /* USER CODE END Init */

 /* Configure the system clock */
 SystemClock_Config();

 /* USER CODE BEGIN SysInit */
 set_OB();
 /* USER CODE END SysInit */

 /* Initialize all configured peripherals */
 MX_GPIO_Init();
 MX_DMA_Init();
 MX_USART1_UART_Init();
 MX_ADC1_Init();
 MX_RTC_Init();
 MX_TIM16_Init();
 MX_IWDG_Init();
 /* USER CODE BEGIN 2 */
 Application();		// Call Application
 /* USER CODE END 2 */

 /* Infinite loop */
 /* USER CODE BEGIN WHILE */
 while (1)
 {
 /* USER CODE END WHILE */

 /* USER CODE BEGIN 3 */
 }
 /* USER CODE END 3 */
}