Kallzu theme does not have a feature where you can insert pixels on individual pages.
Here is how you can insert pixel sitewide:
In kallzu Theme, you can paste the pixel code by visiting
Dashboard --> Kallzu --> SITE SETTINGS --> Header
This will put a tracking pixel on ALL PAGES.
For placing pixel on individual pages, you will have to paste the pixel coded by editing the page
and inserting the code by changing over to the Text Tab of editor in WordPress.
There are a wide variety of free plugins you can install from the WordPress plugin library which will help you install pixels as well.