Permanently show Custom Fields in Editor

Question

I would like to show certain Custom Fields below my Editor. At the moment I only have athe dropdown field but there's so many metas inside which I am not using. By publishing 60-100 posts a day it is really time consuming searching for the respective custom field.

I found the following code somewhere to permenantly display the Custom Field but it does not seem to work.

add_action( 'add_meta_boxes_tender', 'lamosty_add_tender_meta_data' );

function lamosty_add_tender_meta_data( WP_Post $tender ) {
        // Add the meta data you want the custom post type to have
    $tender_meta_data = [
        'briefing',
        'closing',
        'rfirfqnumber',
        'download'
    ];

    foreach ( $tender_meta_data as $meta ) {
        add_post_meta( $tender->ID, $meta, '', true );
    }
}
?>

My desired outcome is that every time I create a new Post the respective Custom Fields are always there and I don't need to look them up in the dropdown. For example like the picture below.

Pleas note that for every new post the values of the Custom Field change!

Do I or does my request make sense?

Answer 1

this should work but you overwrite the values for existing objects.

to add default values only for new objects try that :

$postType = "tender";

add_action( 'save_post_' . $postType, function ($post_ID, \WP_Post $tender, $update) {

    if (!$update) {
        // default value for new object

        // Add the meta data you want the custom post type to have
        $tender_meta_data = [
            'briefing',
            'closing',
            'rfirfqnumber',
            'download',
        ];

        foreach ( $tender_meta_data as $meta ) {
            add_post_meta( $tender->ID, $meta, '', true );
        }


        return;
    }



}, 10, 3);