Help with the hook

Does anybody know how this hook works: If you know the ID of the input, you can also use the wpcf7_hidden_field_value_[#ID] filter.

I have the following but it does not work:

function filter_wpcf7_hidden_field_value_id_att( $value ) { 
        global $wpdb;
    $uniqueid = $wpdb->get_var("SELECT MAX(<code>data_id</code>) FROM <code>wp_cf7_vdata_entry</code> WHERE 1");
    return $uniqueid;
}; 
         
// add the filter 
add_filter( "wpcf7_hidden_field_value_ID123", 'filter_wpcf7_hidden_field_value_id_att', 10, 1 ); 

The field is configured as this: [hidden hidden-731 id:ID123]

any help appreciated.