Camera Module 3 / PiCamera not working on Ubuntu Raspberry Pi

I have a Raspberry pi 4B with Ubuntu, and I’m trying to use my camera module 3 with python (I’ve tested the code with Raspberry Pi OS, so I know it’s right) using PiCamera and in a virtual environment (because otherwise I wouldn’t be able to install external packages). However, when I run the code, it says:

Traceback (most recent call last):
  File "/home/flamethrower/Desktop/CameraCode/headshots_picam.py", line 2, in <module>
    from picamera import PiCamera
  File "/home/flamethrower/cameravenv/lib/python3.11/site-packages/picamera/__init__.py", line 72, in <module>
    from picamera.exc import (
  File "/home/flamethrower/cameravenv/lib/python3.11/site-packages/picamera/exc.py", line 41, in <module>
    import picamera.mmal as mmal
  File "/home/flamethrower/cameravenv/lib/python3.11/site-packages/picamera/mmal.py", line 49, in <module>
    _lib = ct.CDLL('libmmal.so')
           ^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.11/ctypes/__init__.py", line 376, in __init__
    self._handle = _dlopen(self._name, mode)
                   ^^^^^^^^^^^^^^^^^^^^^^^^^
OSError: libmmal.so: cannot open shared object file: No such file or directory


------------------
(program exited with code: 1)

I've tried a test code, but it says the same thing. What should I do?