Can’t display iframe on Neve Header

Hi @romainbo24,

That’s expected and WordPress does not allow to place iframe for security reasons.

If you want to allow iframe to be saved you can place this in the functions.php file (if you’re using a child theme):

function custom_wpkses_post_tags( $tags, $context ) {

	if ( 'post' === $context ) {
		$tags['iframe'] = array(
			'src'             => true,
			'height'          => true,
			'width'           => true,
			'frameborder'     => true,
			'allowfullscreen' => true,
		);
	}

	return $tags;
}

add_filter( 'wp_kses_allowed_html', 'custom_wpkses_post_tags', 10, 2 );

If you’re not using a child theme follow this method:
https://docs.themeisle.com/article/889-how-to-create-a-site-specific-plugin

I hope it helps!