It's always good to include the version number pof the product your using.
for this to work, you will need to upload the wa_evaluate.php file from the Power Galley 1 Database integration update to your site.
on the Power Gallery 2 add to site page, you will need to take a look at the PHP code, and modify it, for example, the PHP code for my galery shows as:
$pg_id = '1';
$pg_theme = 'dark';
this needs to be converted to a hidden form element using the $pg_id value for the id, the $pg_theme value for the theme and the include path for the value:
<input type="hidden" name="powergallery" id="1" theme="dark" value="/Applications/MAMP/htdocs/pg_120/galleries/ribbon_fullsize/index.php" />
this code is what you past in the CMS Content area.
On the page where you output the cms content:
<?php echo WA_getCMSContent($database_PowerCMSConnection, $PowerCMSConnection, 'Content Name' , 'Content Area'); ?>
edit that code to :
<?php require_once("wa_evaluate.php" ?>
<?php echo wa_evaluate(WA_getCMSContent($database_PowerCMSConnection, $PowerCMSConnection, 'Content Name' , 'Content Area')); ?>