How to prevent IFRAME from redirecting top-level window

I use sandbox=”…”

• allow-forms allows form submission
• allow-popups allows popups
• allow-pointer-lock allows pointer lock
• allow-same-origin allows the document to maintain its origin
• allow-scripts allows JavaScript execution, and also allows features to trigger automatically
• allow-top-navigation allows the document to break out of the frame by navigating the top-level window

Top navigation is what you want to prevent, so leave that out and it will not be allowed. Anything left out will be blocked

ex.

<iframe sandbox="allow-same-origin allow-scripts allow-popups allow-forms" src="http://www.example.com"</iframe>