how do I open Digital booklet in audiobook Outlive?

I purchased the audiobook a few days ago and have been listening to outlive and one of the chapters is referencing the PDF files attached so I opened up the digital booklet PDF, but I only get a screen on my phone that shows digital booklet (see picture attached). After tapping it everywhere nothing is opening up and there are several charts and graphs. How do I open the pdfs, are they stored somewhere else?