Users fields are always empty using Tweepy Paginator APIv2

Question

I'm trying to pull tweets by keywords and collect information on the users to analyze the texts they posted, the following is my code:

def get_tweets(self, keywords, num_tweets):
    # Form a search query using all keywords
    query = " OR ".join(keywords) + " -is:retweet lang:en"

    # Define the fields to be returned in each Tweet object
    tweet_fields = ['id', 'text', 'created_at', 'lang', 'public_metrics', 'context_annotations', 'author_id']
    user_fields = ['username', 'description', 'location', 'verified']

    tweets = tweepy.Paginator(self.client.search_recent_tweets, 
                              query=query, 
                              expansions=['author_id'],
                              tweet_fields=tweet_fields,
                              user_fields=user_fields,
                              max_results=100).flatten(limit=num_tweets)
    
    tweet_data = []
    for tweet in tweets:
        if 'includes' in tweet.data and 'users' in tweet.includes:
            users = {u["id"]: u for u in tweet.includes.get('users', [])}
            user = users.get(tweet.data['author_id'], {})
        else:
            user = {}
        
        tweet_data.append({
            'id': tweet.data['id'], 
            'username': user.get('username', ''), 
            'text': tweet.data['text'], 
            'created_at': tweet.data['created_at'], 
            'lang': tweet.data['lang'], 
            'public_metrics': tweet.data.get('public_metrics', ''), 
            'context_annotations': tweet.data.get('context_annotations', ''), 
            'description': user.get('description', ''),
            'location': user.get('location', ''),
            'verified': user.get('verified', ''),
        })

    # Convert the list of tweet data into a DataFrame
    df = pd.DataFrame(tweet_data)
    df.to_csv('tweetsf1.csv', index=False)

This is how I call the def to search by key terms:

# Pass a list of keywords to the function, TwitterClient is a class that includes token info
client = TwitterClient()

client.get_tweets(["test", "test app", \
                                         "test example"], \
                                        1000)

For some reason, all the fields under users are empty, such as username, description , location , and verified. This doesn't happen if I use client.get_tweet, but that will require too many requests , there are only 60 requests per every 15 mins, and it may require 4 hrs to pull 1000 tweets. I can only afford the basic plan.