What signal receives a python program converted into an .exe (with auto_py_to_exe) from NSSM stop service command? Windows O.S

Question

I have this python program:

import logging
import time
import signal
import sys

class ClarkeTest:
    
    def __init__(self):
        # Configure logging
        logging.basicConfig(filename='clarke_test.log', level=logging.INFO, format='%(asctime)s - %(levelname)s - %(message)s')
        
        # Set up signal handler for SIGINT (Ctrl+C)
        signal.signal(signal.SIGINT, self.signal_handler)
        signal.signal(signal.SIGTERM, self.signal_handler) 
    
    def signal_handler(self, sig, frame):
        logging.info("Received SIGINT. Exiting...")
        sys.exit(0)
        

    def main(self):

        while True:
            logging.info("Hello Victor")
            time.sleep(5)

if __name__ == "__main__":
    ClarkeTest().main()

When I execute this program in the console, and press "ctrl+c" a sigint signal is sent to my program, so it logs this message: logging.info("Received SIGINT. Exiting...")

When I converted the python program to .exe with auto_py_to_exe and I installed and started the service with nssm:

1. The loggin in the infinite loop works well
2. The python program (.exe) does not receive the control-c signal (sigint). Therefore the method signal_handler is not executed.

So what signal is the python program receiving and I can monitor to do cleanup/execute signal handler method when service stops?

Many thanks.