Exit script & kill thread when closing the App

[Soif2Sang]

Hello !
Currently when I close the app, the threads summoned by the script are still running. I would like to kill the script including threads when I close the app.
I tried :
page.window_close = lambda : exit()
page.window_destroy = lambda :exit()
page.on_disconnect = lambda :exit()
page.on_close= lambda :exit()

But the threads are still running in the background, can you help me ?

[Soif2Sang]

Issue found, it was not related to flet. My thread were not set as Deamon