How to change Python default

I'm using Python with VScode, but I can't import the package.

import pand as pd
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>        
ModuleNotFoundError: No module named 'pandas'

So I found out that there was a difference in the interpreter and that it was due to the difference in routes.

If you type the command python3, the old version comes out, not the Python version I downloaded.

python3
Python 3.8.10 (default, Jun  2 2021, 10:49:15)
[GCC 9.4.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
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I heard that default is in line with the past version, but I don't know how to change default. I'd really appreciate your help.