but the PDF was created without the necessary administrative rights. In other words, Adobe Reader won't let you add text. What you need is a program that's a little more accommodating, PDF-wise.

The free version of Foxit PDF Reader lets you add a text box to your PDF files. To do this, follow the steps given below: After doing this, click anywhere on your PDF file. A text box will appear ...

The first time you open the app, you'll have the option to set the app to open by default anytime you open a PDF file. Once your file is open, tap anywhere on the screen add a text box.