Yes, @Nick654, on a laptop, go to your inbox and open the message thread with that guest. At the left you will see "About this guest". Under that is a long email address. It has been temporarily generated by the system, and so is full of strange letters and numbers. That's okay. Just use it from your own email to send the guest a pdf, doc, or photo.
@Nick654@Lawrene0 messages sent this way often end up in spam folders, so check to make sure your guest receives it. Another option is to send it as a JPG file via the Airbnb app or website.