如果您使用的是Django，则可能有

If you're using Django, it's possible that you have the Clickjacking middleware installed. Look for this in your settings.py.

MIDDLEWARE_CLASSES = [
    ...
    'django.middleware.clickjacking.XFrameOptionsMiddleware',
    ...
]

这将从您的应用程序服务器发送回Apache，然后Apache将其作为传递HTTP标头发送到浏览器.

This would be sent back from your app server to Apache, and Apache would send it to the browser as a pass-through HTTP header.