Adding tracking codes allows you to track the progress of your campaign's performance. Knowing the performance of your campaign gives you a better direction on how to adjust or improve your campaign. You can get these codes from 3rd party trackers like Google Analytics and Facebook Pixels then just insert it to your campaign to start tracking.
From the dashboard, click on your campaign to open the Campaign Builder. On the upper right side of the Campaign Builder, click the Campaign Settings dropdown and select the Campaign Tracking Codes. This will open up a window to paste in your codes.
Enter the custom scripts on the text area. Click the tabs to choose which area the scripts should appear.
<head> - enter scripts to place in the <HEAD> of the every page in the campaign
<body> - enter scripts to place after the OPENING <BODY> tag
</body> - enter scripts to place before the CLOSING </BODY> tag