error with nltk

app.py

@@ -12,6 +12,7 @@ import base64
 from tqdm.auto import tqdm
 import math
 from transformers import pipeline
+import nltk
 
 from collections import Counter
 from nltk.corpus import stopwords

requirements.txt

@@ -10,3 +10,4 @@ backoff
 tqdm
 openai
 PyMuPDF  # instead of fitz
+nltk