name 'collection_name' is not defined

[Georgi724]

I get this traceback:

Ignoring exception in on_message
Traceback (most recent call last):
File "C:\Users\koynov\AppData\Local\Programs\Python\Python39\lib\site-packages\discord\client.py", line 343, in _run_event
await coro(*args, **kwargs)
File "C:\USERS_KK\python\discord.py\ebay\paggy\levelsys.py", line 28, in on_message
stats = collection_name.find_one(
NameError: name 'collection_name' is not defined