Why is the content in the iframe not opening?

Question

HTML

Please tell me why the video does not open in the iframe by creating an html file locally on the PC or placing the html code on your website. Yandex somehow manages to open the same links through an iframe .

<iframe src="http://hdgo.cc/video/t/n13hu02ata40ivzstvnmxex3/404609/" width="610" height="370" border="0" frameborder="0" allowfullscreen></iframe>

Content is not available in your region.
We apologize for the inconvenience.
Sorry, video was deleted. Error[904]

or

<iframe id="moonp" src="http://cdn.dorama.co/serial/61eb72db02637b73e3282b452dd3a197/iframe?season=01&episode=01&nocontrols_translations=1&nocontrols=1&block_ua=1" width="725" height="410" frameborder="0" webkitallowfullscreen="" mozallowfullscreen="" allowfullscreen=""></iframe>

Content is not available in your region.
We apologize for the inconvenience.
Sorry, video was deleted. Error[902]

Answer 1

It seems that the answer is already there - Content is not available in your region.
The server checks the IP of the requester and refuses to return it to you, since your IP is "bad".
And Yandex - probably drives through itself

Answer 2

The service responds to the referer. If you open the source code in the inspector and add a link directly to this url from the iframe, then it will open; if you open the link directly from the iframe, there will be an error.