where and what are these "non-whitelisted sites"?

“non-whitelisted sites” => “red-light”, “nulled” and so on…

I believe it means you can manually whitelist some sites with the wp_oembed_add_provider function…

and where should this go? There’s no setting’s page of this plugin?!?!

Nope, no settings page. That’s a function for developers to use to customize their sites. Did you click the link? It says right there in the Description at the top:

This function should be called from a plugin or a theme’s functions.php file.

Hey there,

Sorry for my late reply!

There’s no settings page for this plugin because it’s not needed. It does one job and it does it well.

Since WordPress 2.9 it includes a list of whitelisted oEmbed providers by default, for example YouTube and Twitter. Here’s a full list: https://developer.www.ads-software.com/reference/hooks/oembed_providers/

This plugin does not remove these trusted sources, as it isn’t the intention. The plugin removes the ability for others to embed your site and your ability to embed non-whitelisted sites (read: other WordPress sites).

If you want to add sites to the whitelist, use wp_oembed_add_provider() in your plugin or theme. To remove, use wp_oembed_remove_provider(). The following example removes the WordPress TV provider:

wp_oembed_remove_provider( 'https://wordpress.tv/*' );

I’m marking this topic as resolved. If you have more questions regarding how to whitelist oEmbed providers, I suggest asking in the general support forums or on IRC.