I have a website where buyers and sellers are logging in using their unique id. They will be visiting various product pages once logged in. Using Google Analytics API, I would like to display the details of each buyer or seller, with the time they spent in a product page, the pages they visited, etc., in my website backend.
However I am not able to get the UserID, which is important to display the user name and other information, using the google API code.
The same details are visible when I download the data as an excel sheet from google analytics dashboard.
Is there any restriction in APIs that the UserID will be not passed? How we can achieve this otherwise?