Super quick question/clarification/waiting to use plugin

Hi Jeremy (or anyone who can help!)

I posted that the attached images in Post by Email show up again at the bottom of the post as an inline image, and asked if there was a way to –

*** Get rid of the inline image altogether ***

Jeremy Herve said:

While Jetpack doesn’t offer that option, you could automatically remove featured images from the post content by filtering the_content in a separate plugin.

I haven’t tested it, but something like this could work:

/**
* Remove Featured Image from the post content.
*
* @see https://ww.wp.xz.cn/support/topic/2930158
*/
function jeherve_rm_featured_content( $content ) {
// Let’s get info about the featured image first.
$post_thumbnail = wp_get_attachment_image_src( get_post_thumbnail_id() );

// Let’s build a pattern: our image, in an image tag
$image = sprintf(
‘!<img.*?src=”%s”.*?/>!i’,
$post_thumbnail[0]
);

// Remove the image from the post content.
$content = preg_replace( $image, ”, $content );

return $content;
}
add_filter( ‘the_content’, ‘jeherve_rm_featured_content’ );

My question is:
Could you tell me if I can copy & paste this somewhere?

I didn’t quite catch what filtering the_content in a separate plugin means.

What’s the name of the plugin?
Do I find/activate the plugin, then paste this code in it?
If so, where?
Thanks a lot.

https://ww.wp.xz.cn/plugins/jetpack/