Can I embed a Microsoft Teams video meeting into my website using an iframe or other technology?
When I tried, I got this error:
Refused to display 'https://teams.live.com/' in a frame because it set 'X-Frame-Options' to 'sameorigin'.
Can it be cheated somehow?
No you can't. The error message is telling you exactly why not: Microsoft have set a HTTP header in the Teams site which instructs the browser not to load the page into any kind of frame unless that frame is within the teams.live.com website.
The MDN documentation for X-Frame-Options says
The X-Frame-Options HTTP response header can be used to indicate whether or not a browser should be allowed to render a page in a
<frame>,<iframe>,<embed>or<object>. Sites can use this to avoid click-jacking attacks, by ensuring that their content is not embedded into other sites
This is not something you can override - if you could, setting the header would immediately become completely pointless, since anyone with malicious intent would simply choose to ignore it.