I download a piece of work data from the Aozora Bunko and use Janome to make a program that gets parts of speech, but I get an error when I install janome. What should I do?

import urllib.request
from janome.analyzer import Analyzer
from janome.charfilter import *
from janome.tokenizer import Tokenizer

class MainTextCharFilter (CharFilter):
    def __init __ (self, start, end):
        self.start = start
        self.end = end
    def apply (self, text):
        return text.split (self.start) [1] .split (self.end) [0]
# Natsume Soseki
# I'm a cat
html = ''
with urllib.request.urlopen (url) as response:
    html = response.read (). decode ('shift_jis')

char_filters = [UnicodeNormalizeCharFilter (),
                MainTextCharFilter ('<div>', '<div>'),
                RegexReplaceCharFilter ('<rp>\ (. *? \)</rp>', ''),
                RegexReplaceCharFilter ('<. *?>', '')]
tokenizer = Tokenizer ()
analyzer = Analyzer (char_filters, tokenizer)
for token in analyzer.analyze (html):
    print (token)

Traceback (most recent call last):
  File "directory name", line 3, in<module>
    from janome.analyzer import Analyzer
ModuleNotFoundError: No module named 'janome'