Graphs - Navigation Tool Bar Not Showing Up

import sys
 
from PyQt5.QtWidgets import QApplication, QMainWindow, QMenu, QVBoxLayout, QSizePolicy, QMessageBox, QWidget, QPushButton
from PyQt5.QtGui import QIcon
 
 
from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.figure import Figure
from matplotlib.backends.backend_qt5agg import NavigationToolbar2QT as NavigationToolbar
import matplotlib.pyplot as plt 
import random
 
class App(QMainWindow):
 
    def __init__(self):
        super().__init__()
        self.left = 100
        self.top = 100
        self.title = 'PyQt5 matplotlib example - pythonspot.com'
        self.width = 640
        self.height = 400
        self.initUI() #not sure what this line of code does
        self.fig=Figure()
        self.canvas=FigureCanvas(self.fig)
        #add plot toolbar from matplotlib
        self.toolbar = NavigationToolbar(self.canvas, self)
 
    def initUI(self):
        self.setWindowTitle(self.title)
        self.setGeometry(self.left, self.top, self.width, self.height)
 
        m = PlotCanvas(self, width=5, height=4)
        m.move(0,0)
 
        button = QPushButton('PyQt5 buttons', self)
        button.setToolTip('This is an example button')
        button.move(500,0)
        button.resize(140,100)
 
        self.show()
 
 
class PlotCanvas(FigureCanvas):
 
    def __init__(self, parent=None, width=5, height=4, dpi=100):
        fig = Figure(figsize=(width, height), dpi=dpi)
        self.axes = fig.add_subplot(111)
 
        FigureCanvas.__init__(self, fig)
        self.setParent(parent)
 
        FigureCanvas.setSizePolicy(self, QSizePolicy.Expanding,QSizePolicy.Expanding)
        FigureCanvas.updateGeometry(self)
        self.plot()
 
 
 
    def plot(self):
        data = [random.random() for i in range(25)]
        ax = self.figure.add_subplot(111)
        ax.plot(data, 'r-')
        ax.set_title('PyQt Matplotlib Example')
        self.draw()
 
if __name__ == '__main__':
    app = QApplication(sys.argv)
    ex = App()
    sys.exit(app.exec_())