@ShreeHarshaN16839089To add a reference to an assembly in a script,

1. Open the script object.
2. Click the Manage references button above the script editor.
3. Locate the assembly you wish to add a reference to along with any of that assemblies references.
4. Click the add button to add the reference.
5. Add the "using" statement to import that namespace into the script.

If your assembly is not one already present in the installation folder for Pega Studio or it is not one already present in .Net, you'll need to place it along with any of its references in the %AppData%\PegaSystems\PublicAssemblies folder. Once here, you can then follow the steps above to add the reference into your script.

Incidentally, you might not need to use a script to do what you're trying to do. Pega Robotics Studio has great support for reading PDFs and can even fill out PDF forms and even highlight some PDFs.