The free version of Adobe XD provides only 2 free export to PDF files. You cannot export to PDF files after you have used the 2 free export to PDF. I tried to search if there are any other easy and fast methods to do so without using any cracked software and I devised this simple trick.
Convert to PNG file
The free version of Adobe XD allows you to export your XD files to PNG and SVG as much as you want. This is the trick here. Open your XD file and go to Files and Export. Then export your XD file to PNG.
Install Awesome Screenshot Chrome Extension
Install Google Chrome extension called Awesome Screenshot to your browser. Activate the plugin on your browser. You can also pin the extension for your convenience.
Convert PNG file to PDF
Now open the exported PNG file using your Google Chrome browser in 100% view. Then, capture a full screenshot of the complete page from top to bottom using the Awesome Screenshot extension.
Finally, export the captured full screenshot to PDF and download it.