Adds settings to the 'default' landing page template via custom plugin code or an active theme's functions.php file

example.php

<?php

add_filter('lp_extension_data','lp_rebuild_old_data_configurations_to_suit_new_convention');
function lp_rebuild_old_data_configurations_to_suit_new_convention($lp_data)
{

   $lp_data['default']['settings']['new_setting'] =   array(
        'label' => "New setting",
        'description' => "Description of new setting here. Will be placed in tooltip"
        'id'  => 'new_setting',
        'type'  => 'dropdown',
        'default'  => 'off',
        'options' => array('off'=>'Turn off','on'=>'Trun On'),
        'context'  => 'normal'
  );
 
}

This doesn't parse. Needs a comma at the end of the description line.

when I place this code in my theme's functions.php, I get
Fatal error: Cannot redeclare lp_rebuild_old_data_configurations_to_suit_new_convention() in /nas/wp/www/sitename/wp-content/themes/my-theme/functions.php on line x