brew install pyqt5
echo 'export PATH="/opt/homebrew/opt/qt@5/bin:$PATH"' >> ~/.zshrc
echo 'export PATH="/opt/homebrew/opt/pyqt@5/5.15.4_1/bin:$PATH"' >> ~/.zshrc
source ~/.zshrc
from
/opt/homebrew/Cellar/pyqt@5/5.15.4_1/lib/python3.9/site-packages
all file move to
/Users/[you account name]/miniforge3/lib/python3.9/site-packages
(base) mac-guo@MAC-GUOdeMBP ~ % python
Python 3.9.7 | packaged by conda-forge | (default, Sep 29 2021, 19:24:02)
[Clang 11.1.0 ] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import PyQt5

if normal congratulation you installed PyQt5 successed. Otherwise you are failed, please see the detail what print.
Best Regards.
Thanks!