Files for my tutor

When I share my files to my tutor, it can’t access it. They’re in PDF, and I can see them on the right of my screen, but when I ask my tutor to explain something, it says they don’t have access to it. What can I do? I enclose a screenshot. As you can see, it says it can't read the shared file.

What I’m doing right now, is paste the text, but it’s not very helpful…