Customize a popup

[ldelaroque]

Hi! I'm currently using PyQt5 and pyqtlet to create an application and display an L.map in it with a marker, and I have associated a popup for this marker. I've managed to embed an HTML button in this marker, and I'd like to run a function in python when the user clicks on this button. Do any of you have an idea how I could do this? :)
Here is my code:

import sys
import webview
import js2py
import os


from PyQt5.QtGui import QTextDocument
from PyQt5.QtWidgets import QDialog, QPushButton
from PyQt5.QtWidgets import QApplication, QMainWindow

from PyQt5.QtWebEngineWidgets import QWebEngineView
from PyQt5.QtWebChannel import QWebChannel
from pyqtlet import L, MapWidget

from PyQt5 import QtCore
from PyQt5.QtCore import pyqtSlot, QTimer,Qt, QObject
from flask import Flask,jsonify

app = Flask(__name__)


class Window(QMainWindow):
    def __init__(self, parent=None):

        super().__init__(parent)
        
        self.mapWidget = MapWidget()
        self.setCentralWidget(self.mapWidget)
        self.webChannel=QWebChannel(self.mapWidget.page)
        QtCore.QMetaObject.connectSlotsByName(self)

        # MAPPING
        self.map = L.map(self.mapWidget)
        self.map.setView([0, 0], 2)
        L.tileLayer('http://{s}.tile.osm.org/{z}/{x}/{y}.png').addTo(self.map)
        
        self.marker = L.marker([48.8566, 2.3522])
        self.map.addLayer(self.marker)

        
        popup_html = "<button id='MyButton' type='button' class='btn btn-primary sidebar-open-button' onclick='open_window()'>Click me</button>"
        
        def open_window(self):
            dialog = QDialog(self)
            dialog.exec_()

        
        '''
        popup_js = """
        <script src="https://code.jquery.com/jquery-3.6.0.min.js"></script>
        <script>
            function appelerFonction() {
                $.ajax({
                    url: "/appeler_fonction",
                    type: "POST",
                    success: function() {
                        console.log("The function has been successfully called!");
                    },
                    error: function() {
                        console.log("An error occurred when calling the dunction.");
                    }
                });
            }
        </script>
        """
        
        popup_content = popup_html + popup_js
        '''
        
        self.marker.bindPopup(popup_html)

        


    
if __name__ == "__main__":

    app = QApplication(sys.argv)
    win = Window()
    win.show()
    sys.exit(app.exec_())

In fact, when I run the code, it works quite well but I got this error in my console: "js: Uncaught ReferenceError: open_window is not defined" and I don't know how to fix it. Thanks you all,