Adds hidden input fields to the meta box save form.
Description
Hook into this action to print <input type="hidden" ... /> fields, which will be POSTed back to the server when meta boxes are saved.
Parameters
$post
WP_Post
The post that is being edited.
Source
File: wp-admin/includes/post.php.
View all references
do_action( "block_editor_meta_box_hidden_fields", $post );