Unable to access shared review features (publish comments)

Specs:
Acrobat Reader DC version 2018.011.20038 (up to date)

Mac OSX 10.13.4 (up to date)

Problem:

I was emailed a PDF document to review through the shared review process. However, the document opens like a normal PDF - no attempt to connect to any server is made, and no toolbar for comments and annotations nor any button to publish comments appears.