python -m PyInstaller --onefile test.py

import sys
from PyQt5.QtCore import *
from PyQt5.QtWidgets import *
from PyQt5.QtWebEngineWidgets import *

class MainWindow(QMainWindow):
def __init__(self):
super(MainWindow, self).__init__()
self.browser = QWebEngineView()
self.browser.setUrl(QUrl('WEB_SITE_URL'))
self.setCentralWidget(self.browser)
self.showMaximized()

app = QApplication(sys.argv)
QApplication.setApplicationName('Safe Browser')
window = MainWindow()
app.exec_()