Using the PDF Themes feature of Tally you can add additional pages to your documents, to do that just follow the steps below.
Creating a New Theme
The first step is to create a new theme or modify your existing one, access that by going to Settings > PDF Themes. Please note that if you're currently using the Classic or Clean theme you will need to create a new theme as the HTML and CSS of these cannot be modified.
Editing the HTML
The next step is to edit the HTML of your theme to add the additional content - don't worry, this isn't as scary as it sounds! Do that by clicking the HTML & CSS tab and edit the content of Document.HTML. Scroll to the bottom of the page; you'll need to insert your content BEFORE the following:
Before the final </div> insert the following:
<p>Whatever content you like</p>
Replace the text between the <p> and </p> to anything you like. You can also include images, advanced formatting and more within that section although this will require some knowledge on HTML and CSS. For more information have a chat with your web designer or have a read of W3Schools.