Unable to stop a while loop in djnago chanels after receiving a message (Trying to do a timer using while and asyncio)

I want to stop the while loop when i receive new message how can i do this I am doing this task each time receiving a message from the front end (Its Like A timer, when i press the button the timer start and if the timer == 20s or the button is pressed again the timer will restart)

restarting = True
i = 0
restarting = False

while restarting == False :
    i += 1
    await asyncio.sleep(1)
    if i == 20 or restarting == True :
        await self.channel_layer.group_send(
            self.room_group_name,
            {
                'type': 'starting_timer',
                
                'Timer': i,
            }
        )
        break
    await self.channel_layer.group_send(
        self.room_group_name,
        {
            'type': 'starting_timer',
            
            'Timer': i,
        }
    )

so my problem is when i receive a message before 20s (lets say i pressed the button after 5s) the old timer keep sending messages from the old while loop and send another messages of the restarted timer I want to stop the while loop when i receive new message how can i do this