Matplotlib not found error

Traceback (most recent call last):
  File "/home/appuser/venv/lib/python3.9/site-packages/streamlit/runtime/scriptrunner/script_runner.py", line 565, in _run_script
    exec(code, module.__dict__)
  File "/app/flight_data_analysis/flight.py", line 16, in <module>
    import matplotlib.pyplot as plt
ModuleNotFoundError: No module named 'matplotlib'
2023-04-10 22:23:27.892 Uncaught app exception
Traceback (most recent call last):
  File "/home/appuser/venv/lib/python3.9/site-packages/streamlit/runtime/scriptrunner/script_runner.py", line 565, in _run_script
    exec(code, module.__dict__)
  File "/app/flight_data_analysis/flight.py", line 16, in <module>
    import matplotlib.pyplot as plt
ModuleNotFoundError: No module named 'matplotlib'
[22:23:29] 🔄 Updated app!

I’m getting this error even though I imported it in requirments

Then it is not installed.

Maybe the file name misspelled?