UnboundLocalError: local variable 'toggled' referenced before assignment

Question

I was working on a random python script but I've encountered the above error and cannot figure out how to work it out.

Code:

from pynput.keyboard import Key, Controller, Listener
import time

keyboard = Controller
key = "e"
toggle = Key.f6
toggled = False

def on_press(key):
    print(f"on_press() triggered, key = {key}")
    if key == toggle:
        toggled = not toggled

def on_release(key):
    print(f"on_release() triggered, key = {key}")

with Listener(on_press=on_press, on_release=on_release) as listener:
    listener.join()

while True:
    if toggled:
        keyboard.press(key)
        time.sleep(3)
        keyboard.release(key)
        time.sleep(1)