You can apply redeem code to install Premium Add-on for Chinese and Japanese language.
How to install Premium Add-on using redeem code
Step 1: Sign in on GlotDojo page with your account.
Step 2: Open Redeem in your Account Settings
Step 3: Enter the code you receive in the following box:
Step 4: After entering the code, click Redeem. You have successfully purchased Premium Add-on.
After successfully purchasing Premium Add-on with redeem code, you need to download the dictionaries to be able to look up words with the Premium Add-on.