How can I use parent variable in child file at flask blueprint mode?

Question

I want to access same webcam resource and dispatch the frame to different router. And support multiple clients.

To achieve this I reference flasky and pyimage.

This is my code simple architecture

My code snippet as following: - init.py

from flask import Blueprint
import threading
import cv2
from flask import Response
import time

api = Blueprint('api', __name__)

outputFrame = None
lock = threading.Lock()

camera = cv2.VideoCapture(0)
time.sleep(2.0)


def get_frames():
    global camera, outputFrame, lock

    while True:
        success, frame = camera.read()
        if not success:
            print("If not success")
            break
        else:
            with lock:
                outputFrame = frame.copy()
    

from . import fileA

- fileA.py

from . import api ,outputFrame, lock
from flask import render_template, Response
import cv2
import threading

def gen_frames():
    while True:
        with lock:
            if outputFrame is None:
                continue

            (flag, encodedImage) = cv2.imencode(".jpg", outputFrame)

            if not flag:
                continue

        yield(b'--frame\r\n' b'Content-Type: image/jpeg\r\n\r\n' + 
            bytearray(encodedImage) + b'\r\n')


@api.route('/templateA/')
def page():
    return render_template("fileA.html")

@api.route('/video_feed')
def video_feed():
    return Response(gen_frames(),
                    mimetype='multipart/x-mixed-replace; boundary=frame')

The output is : outputFrame is None.
How can I get this frame information in fileA?
Any help will appreciate.