基于Graph API的Facebook Messenger机器人仅本人可用，如何开放给公众？

我已通过两篇教程，使用Graph API成功创建了Facebook Messenger机器人。该机器人在我本人使用页面Messenger时运行正常，但无法响应其他用户，且我已将应用设为上线状态。作为新手我无法定位问题，请问我遗漏了哪些步骤？为何机器人无法回复其他用户？

以下是我的代码：

PAGE_ACCESS_TOKEN='EAAO------'
API = "https://graph.facebook.com/v17.0/me/messages?access_token="+PAGE_ACCESS_TOKEN

@app.route("/", methods=['GET'])
def fbverify():
    if request.args.get("hub.mode") == "subscribe" and request.args.get("hub.challenge"):
        if not request.args.get("hub.verify_token")==PAGE_ACCESS_TOKEN:
            return "Verification token missmatch", 403
        return request.args['hub.challenge'], 200
    return "Hello", 200


@app.route("/", methods=['POST'])
def fbwebhook():
    data = request.get_json()
    print(data)
    
        # Read messages from facebook messenger.
    message = data['entry'][0]['messaging'][0]['message']
    print(message)
    sender_id = data['entry'][0]['messaging'][0]['sender']['id']
    print(sender_id)
    if message['text']:
        # Response from chatbot_handler
        response_text = chatbot_handler(message['text'], chat_history)  
        
        request_body = {
            "recipient": {
                "id": sender_id
            },
            "message": {
                "text": response_text  # Use the response from chatbot_handler
            }
        }
        
        response = requests.post(API, json=request_body).json()
        return response

恳请各位提供帮助，谢谢！

内容的提问来源于stack exchange，提问作者AqashaT