Different output when i use function or directly, cant understand why

Question

If i use it like this, output is always 0:
(test3 is a button, lambda fun is called on click, test3)

def fun(spawn):
print(f"Reaction:{pygame.time.get_ticks()-spawn}")
test3.random_click(event,lambda:fun(test3.spawntime))

But if i print it directly, its working normally (numbers are growing but nullified on click(cuz of spawntime is changing )

Full code: https://code.sololearn.com/ch0yG1XQhI5d

Answer 1

Maybe because print(f"Reaction:{pygame.time.get_ticks()-test3.spawntime}") has the wrong formating

Answer 2

Whats wrong about this?