custom fields primary category

add_action( 'save_post', 'custom_jnews_parimary_cat', 100 );
add_action( 'edit_post', 'custom_jnews_parimary_cat', 100 );

function custom_jnews_parimary_cat( $post_id ) {
    if ( isset( $_POST['acf'] ) ) {
        $jnews_primary_category = array();
        if ( ! empty( $_POST['acf']['field_67a179e3b2922'] ) ) { /* change field_67a179e3b2922 with your Primary Category Fields Key */
            $jnews_primary_category['id'] = $_POST['acf']['field_67a179e3b2922'];
        }

        if ( ! empty( $_POST['acf']['field_67a18042776b6'] ) && is_array( $_POST['acf']['field_67a18042776b6'] ) ) {  /* change field_67a18042776b6 with your Hide Category Fields Key */
            $jnews_primary_category['hide'] = implode( ',', $_POST['acf']['field_67a18042776b6'] );
        }

        if ( ! empty( $jnews_primary_category ) ) {
            update_post_meta( $post_id, 'jnews_primary_category', $jnews_primary_category );
        }
    }
}