Webview Error

Hello everyone. I am having trouble using webview for facebook messenger chatbot. Until a week ago, the webview was running normally in the Facebook messenger chatbot, but since a week ago, the webview is not working. I entered all the credentials, the code on the Rasa server side and the code in flask for webview correctly. I also inserted the Messenger Extension into the HTML and whitelisted domain. But the webview doesn’t work. Any help would be appreciated. Thank you for your reading.