I want to install flask in my virtual environment . I used "pip install flask" commmand ,but I got this error:

raceback (most recent call last):
  File "C:\Users\user\anaconda3\lib\runpy.py", line 194, in _run_module_as_main
    return _run_code(code, main_globals, None,
  File "C:\Users\user\anaconda3\lib\runpy.py", line 87, in _run_code
    exec(code, run_globals)
  File "C:\Users\user\Desktop\news_bot\myvenv\Scripts\pip.exe\__main__.py", line 4, in <module>
  File "c:\users\user\desktop\news_bot\myvenv\lib\site-packages\pip\_internal\cli\main.py", line 10, in <module>
    from pip._internal.cli.autocompletion import autocomplete
  File "c:\users\user\desktop\news_bot\myvenv\lib\site-packages\pip\_internal\cli\autocompletion.py", line 9, in <module>
    from pip._internal.cli.main_parser import create_main_parser
  File "c:\users\user\desktop\news_bot\myvenv\lib\site-packages\pip\_internal\cli\main_parser.py", line 7, in <module>
    from pip._internal.cli import cmdoptions
  File "c:\users\user\desktop\news_bot\myvenv\lib\site-packages\pip\_internal\cli\cmdoptions.py", line 24, in <module>
    from pip._internal.cli.progress_bars import BAR_TYPES
  File "c:\users\user\desktop\news_bot\myvenv\lib\site-packages\pip\_internal\cli\progress_bars.py", line 12, in <module>
    from pip._internal.utils.logging import get_indentation
  File "c:\users\user\desktop\news_bot\myvenv\lib\site-packages\pip\_internal\utils\logging.py", line 18, in <module>
    from pip._internal.utils.misc import ensure_dir
  File "c:\users\user\desktop\news_bot\myvenv\lib\site-packages\pip\_internal\utils\misc.py", line 31, in <module>
    from pip._internal.locations import (
  File "c:\users\user\desktop\news_bot\myvenv\lib\site-packages\pip\_internal\locations\__init__.py", line 7, in <module>
    from pip._internal.models.scheme import SCHEME_KEYS, Scheme
ImportError: cannot import name 'SCHEME_KEYS' from 'pip._internal.models.scheme' (c:\users\user\desktop\news_bot\myvenv\lib\site-packages\pip\_internal\models\scheme.py)

I had updated pip and after updation I am getting this error.

OS:Windows

Python version:3.8.5

Thanks :)