QT-PyQt-PySide-Custom-Widgets error: No library called cairo was found

Question

I've been trying to implement methods to add some shadow effects to some parts of the UI (i.e. the header and footer) and was told to import/install PySide (or PyQt) and QT-PyQt-PySide-Custom-Widgets (note I have PyQt5/6 and PySide6 installed) However, setGraphicsEffects doesn't seem to work. In other words, it acts like there is no said function available. Not only that, but when I run it, it gives me an OS error:

Traceback (most recent call last):
  File "C:\Users\UserPC\OneDrive\Documentos\ProjectSICI\propiedadesmain.py", line 11, in <module>
    from Custom_Widgets.Widgets import *
  File "C:\Users\UserPC\AppData\Local\Programs\Python\Python311\Lib\site-packages\Custom_Widgets\__init__.py", line 12, in <module>
    from Custom_Widgets.Qss.SvgToPngIcons import NewIconsGenerator
  File "C:\Users\UserPC\AppData\Local\Programs\Python\Python311\Lib\site-packages\Custom_Widgets\Qss\SvgToPngIcons.py", line 22, in <module>
    import cairosvg
  File "C:\Users\UserPC\AppData\Local\Programs\Python\Python311\Lib\site-packages\cairosvg\__init__.py", line 26, in <module>
    from . import surface  # noqa isort:skip
    ^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\UserPC\AppData\Local\Programs\Python\Python311\Lib\site-packages\cairosvg\surface.py", line 9, in <module>
    import cairocffi as cairo
  File "C:\Users\UserPC\AppData\Local\Programs\Python\Python311\Lib\site-packages\cairocffi\__init__.py", line 47, in <module>
    cairo = dlopen(
            ^^^^^^^
  File "C:\Users\UserPC\AppData\Local\Programs\Python\Python311\Lib\site-packages\cairocffi\__init__.py", line 44, in dlopen
    raise OSError(error_message)  # pragma: no cover
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
OSError: no library called "cairo-2" was found
no library called "cairo" was found
no library called "libcairo-2" was found
cannot load library 'libcairo.so.2': error 0x7e.  Additionally, ctypes.util.find_library() did not manage to locate a library called 'libcairo.so.2'
cannot load library 'libcairo.2.dylib': error 0x7e.  Additionally, ctypes.util.find_library() did not manage to locate a library called 'libcairo.2.dylib'    
cannot load library 'libcairo-2.dll': error 0x7e.  Additionally, ctypes.util.find_library() did not manage to locate a library called 'libcairo-2.dll'        

Here's the whole script of the file for reference:

import os
import sys

import csv
from propiedades import *


# from PyQt5 import QtCore, QtGui, QtWidgets
# from PyQt5.QtWidgets import QApplication, QMainWindow
# from PyQt5.QtGui import *
# from PyQt5.QtCore import *
from Custom_Widgets.Widgets import *
from PySide6.QtGui import *
from PySide6.QtCore import *
from PySide6.QtWidgets import *
from functools import partial

shadow_elements = { "left_menu","frame_3", "frame_5", "header", "frame_8"}

class MainWindow(QMainWindow):
        def __init__(self,parent=None):
            QMainWindow.__init__(self)
            self.ui = Ui_MainWindow()
            self.ui.setupUi(self)
            
            self.setMinimumSize(850,600)
            
            loadJsonStyle(self, self.ui)
            for x in shadow_elements:
                
                effect = QtWidgets.QGraphicsDropShadowEffect(self)
                effect.setBlurRadius(18)
                effect.setXOffset(0)
                effect.setYOffset(0)
                effect.setColor(QColor(0,0,0,255))
                getattr(self.ui,x).setGraphicsEffect(effect)
            
            
            self.show()
            
if __name__ == "__main__":
    import sys
    app = QApplication(sys.argv)
    window = QMainWindow()
    window.show()
    sys.exit(app.exec_())

AM I missing something? Does it have to do with QT-PyQt-PySide-Custom-Widgets? Note that I'm using Python 3.11. I tried to use Python 3.12 but the PyQt6 tools aren't supported with it.