Kindly try this sample and let us know if your requirement is achieved.
I am creating temple with WordDocument and then I convert them into PDF with DocIORenderer.ConvertToPDF.
What I want is to be able to add an url into the pictures so I can download them on click like the file in example.
Yes, it is possible to meet your requirement with adding an URL into the picture, where the click in the picture of the generated PDF will access the embedded URL which redirect to some other content using our Essential DocIO library. To know more details about adding an URL into the picture, please use our UG documentation page.
In the sample, we have done the following things: 1. Created new instance of Word document. 2. Added section into the Word document. 3. Added the image into the section with hyperlink which redirect to some other contents. 4. Converted the Word document to PDF