Python - Error de autenticación de Tweepy

Estoy haciendo un bot para dar like a ciertos tweets con la libreria de tweepy, y me da un error:

import tweepy
import time
from tweepy import api


# Claves:

consumer_key = 'zzz'
consumer_secret = 'xxx'
access_token = 'vvv'
Access_Token_Secret = 'bbb'
Bearer_Token = "nnn"
# Acceso:
def twitter_setup():
auth = tweepy.OAuthHandler(consumer_key, consumer_secret)
auth.set_access_token(access_token, Access_Token_Secret)

api = tweepy.API(auth, wait_on_rate_limit=True, wait_on_rate_limit_notify=True)
return api

if __name__ == '__main__':

bot = twitter_setup

user = api.verify_credentials()

search = 'Messi'

nrTweets = 50
for tweet in tweepy.Paginator(api.search_tweets, search, nrTweets):
try:
bot.__init__
print('He dado Like')
tweet.favorite()

time.sleep(50)
except tweepy.TweepError as e:
print(e.reason)
except StopIteration:
break

ese es el codigo, y me da este error y no entiendo porque si la autenticacion se supone que esta bien hecha:

Traceback (most recent call last):
File "C:\Users\Eduardo\Desktop\Proyecto #1 Bot de twitter.Py\Likes.py", line 25, in <module>
user = api.verify_credentials()
File "C:\Users\Eduardo\AppData\Local\Programs\Python\Python39\lib\site-packages\tweepy\api.py", line 46, in wrapper
return method(*args, **kwargs)
File "C:\Users\Eduardo\AppData\Local\Programs\Python\Python39\lib\site-packages\tweepy\api.py", line 2570, in verify_credentials
return self.request(
File "C:\Users\Eduardo\AppData\Local\Programs\Python\Python39\lib\site-packages\tweepy\api.py", line 146, in request
raise TweepyException('Authentication required!')
tweepy.errors.TweepyException: Authentication required!