To look up with Premium Chinese/Japanese Add-on, make sure you have downloaded its advanced dictionaries.
2 methods to look up words with the Premium Add-on
Chinese and Japanese are languages of compound words. You can use GlotDojo to detect these compound words. There are 2 ways to do this:
Press and hold the middle mouse (the red button in the image below) and hover to the position of the word.
Press and hold the Shift key (the red button in the image below) and hover to the position of the word.
The two ways to look up words above help you to look up words in newspapers and videos, and look up compound words.
These methods will help you look up on all web pages,
as well as fully-supported video sites.
If GlotDojo detect a compound word, its meaning would be displayed in the Dictionary section of the pop-up as below: