Thank you for your answer. My code is running properly on my computer without any errors. The problem occurs when I try to upload it to the streamlit cloud.
So I think you have misconfigured the app while creating app on Streamlit Cloud. Proof I tried your code and it works flawlessly. So delete that app on Streamlit Cloud maybe and create new one with following settings:
Select Your GItHub Repo.
Check the branch name carefully. (It must be main)
Your main file is wacc.py. Please check this very carefully as I think this is where you may have misspelled it. In your screenshot there is a warning Main module does not exist which is probably result of this final step.
In Advanced I selected Python version 3.9 though I am using 3.10 on my local system.
Try this out, it should probably work as it did for me. I did not change a single line of code or requirements.