Why client.search_recent_tweets( ) couldn't get enough number of tweets?

Question

The code below only collect 5 tweets... I really couldn't figure it out what is wrong with it? Can anyone help me please?

client = tweepy.Client(
    consumer_key=consumer_key,
    consumer_secret=consumer_key_secret,
    access_token=access_token,
    access_token_secret=access_token_secret
)

keywords = '#RadioactiveWaste'
colums = ['User_name', 'Tweet', 'Tweet_ID', 'Time']
data = []
page_num = 35  #collect 3500 tweets

page_num += 1
tweets = []
until_id = None
for i in range(0, page_num,100):
    response = client.search_recent_tweets(query=keywords, max_results=100, user_auth=True, until_id=until_id)
    if len(response.data) == 0:
        break
    tweets_chunk = response.data
    tweets.extend(tweets_chunk)
    until_id = tweets_chunk[-1].id

for tweet in tweets:
    tweet_id =  tweet.id
    tweet_text = tweet.text
    tweet_time = tweet.created_at
    user_id = tweet.author_id
    data.append([tweet_id, tweet_text, tweet_time, user_id])
df = pd.DataFrame(data, columns=colums)
df

I wish the number of tweets I can get reach my setting.