Loop is called thanks:

Your loop take too much time. You should not called delay. In a general way, avoid to use loop, create dedicated task. Moreover, your blink is very quick ( 100 ms)

Check this example:
https://github.com/stm32duino/STM32FreeRTOS/blob/master/examples/frBlinkPrint/frBlinkPrint.ino

thank you but i try you frBlinkPrint.ino example into stm32f103c8t6 led not work

@SocketNet
I've just tried with my BP and it's works fine with HardwareSerial.
Note that if you use USB CDC for Serial then you will have to use the heap management number 3
See #16 (comment)

myconfig

[env:genericSTM32F103C8]
platform = ststm32
board = genericSTM32F103C8
framework = arduino
upload_protocol = serial
board_build.core = STM32

code

  #include <Arduino.h>
  #include <STM32FreeRTOS.h>


  void task(void *pvParameters)
  {
    Serial.println("task start");
    for (;;)
    {
      for (int i = 65; i < 91; i++)
      {
        Serial.println((char)i);
        vTaskDelay(500 / portTICK_RATE_MS);
      }
    
    }
  }

  void setup()
  {
    Serial.begin(9600);
    Serial.println("Serial start");
    xTaskCreate(task, "task", configMINIMAL_STACK_SIZE + 128, NULL, tskIDLE_PRIORITY + 2, NULL);
    vTaskStartScheduler();
    while(1);
  }

  void loop()
  {
    
  }

The console only outputs "A", and the task seems to stop as soon as it arrives vTaskDelay and never continues.

OK, you used PIO.
So, you should open an issue on its GitHub.
It works with Arduino IDE and we don't support PIO.
Maybe you can linked to platformio/platform-ststm32#237

ok Thanks again

@fpistm Please merge this #18 and we will reindex this library in our registry. We need to instruct PlatformIO Build System to not archive library and link as plain objects.