How do I resolve "No module named 'frontend'" error message?

I tried the above solution of pip install PyMuPDF. But it did not work out of the box.

So, I have used the previous version of PyMuPDF. It worked perfectly for me.

pip install PyMuPDF==1.16.14

I've solved it by:

pip install PyMuPDF

This will actually allow the import of the fitz you appear to want. (There's another fitz, which is probably not what you want if you're manipulating PDF files.)