[ARM] UART not responding under OSC BYPASS Mode

char data[] = "Hello World\r\n";
     
    int main(void)
    {
      HAL_Init();
      //SystemClock_Config();
     
      RCC_OscInitTypeDef Osc = {0};
      RCC_ClkInitTypeDef Clk = {0};
     
      Osc.OscillatorType = RCC_OSCILLATORTYPE_HSE;
      Osc.HSEState = RCC_HSE_BYPASS;
      HAL_RCC_OscConfig(&Osc);
     
      Clk.ClockType = RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2;
      Clk.AHBCLKDivider = RCC_SYSCLK_DIV2;
      Clk.SYSCLKSource = RCC_SYSCLKSOURCE_HSE;
      Clk.APB1CLKDivider = RCC_HCLK_DIV2;
      Clk.APB2CLKDivider = RCC_HCLK_DIV2;
     
      HAL_RCC_ClockConfig(&Clk, FLASH_ACR_LATENCY_0WS);
     
      __HAL_RCC_HSI_DISABLE();
     
      HAL_SYSTICK_Config(HAL_RCC_GetHCLKFreq()/1000);
      HAL_SYSTICK_CLKSourceConfig(SYSTICK_CLKSOURCE_HCLK);
     
     
     
      MX_GPIO_Init();
      MX_USART2_UART_Init();
     
      while (1)
      {
       HAL_UART_Transmit(&huart2, (uint8_t*) data, sizeof(data), HAL_MAX_DELAY);
      }
    }