OpenCV can't access the user's camera when deployed on Heroku

Question

I've developed an application using OpenCV. It uses the camera and detects the face using OpenCV. When I use the app on localhost, it works fine, but when I deploy it on Heroku. The app cannot access the camera of the visitor. How can the camera be accessed by the OpenCV application?

Here's the code.

import cv2

faceDetect = cv2.CascadeClassifier('haarcascade_frontalface_default.xml')


class Video(object):
    def __init__(self):
        self.video = cv2.VideoCapture(-1)
        self.video.set(3, 1280)
        self.video.set(4, 720)

    def __del__(self):
        self.video.release()

    def get_frame(self):
        ret, frame = self.video.read()
        frame = cv2.flip(frame, 1)
        faces = faceDetect.detectMultiScale(frame, 1.3, 5)
        for x, y, w, h in faces:
            x1, y1 = x + w, y + h
            cv2.rectangle(frame, (x, y), (x + w, y + h), (255, 0, 255), 1)
            cv2.line(frame, (x, y), (x + 30, y), (255, 0, 255), 6)  # Top Left
            cv2.line(frame, (x, y), (x, y + 30), (255, 0, 255), 6)

            cv2.line(frame, (x1, y), (x1 - 30, y), (255, 0, 255), 6)  # Top Right
            cv2.line(frame, (x1, y), (x1, y + 30), (255, 0, 255), 6)

            cv2.line(frame, (x, y1), (x + 30, y1), (255, 0, 255), 6)  # Bottom Left
            cv2.line(frame, (x, y1), (x, y1 - 30), (255, 0, 255), 6)

            cv2.line(frame, (x1, y1), (x1 - 30, y1), (255, 0, 255), 6)  # Bottom right
            cv2.line(frame, (x1, y1), (x1, y1 - 30), (255, 0, 255), 6)

        ret, jpg = cv2.imencode('.jpeg', frame)
        return jpg.tobytes()