YouTube embeds and Error 153

As part of YouTube's TOS , the embedded player (i.e. iframe ) must provide identification via the HTTP Referer header ( not a typo unfortunately ), otherwise you may end up with the following error: To remedy this, make sure it's at least set to strict-origin-when-cross-origin . Adding referrerpolicy="strict-origin-when-cross-origin" to the iframe alone may not be sufficient.