1. Click on your avatar to open the settings.
2. Change the language to Traditional Chinese (line 2).
3. Go to the Quests / Campaign page and scroll down where you will see 3 quests that require you to subscribe to the official game groups on Discord, Facebook, Youtube and Bahamut (Taiwanese gaming forum).
4. Each quest gives 50 diamonds (if you completed these tasks earlier in another language, then the reward can be received again). Just click the "Join" button and return to the game.
5. Collect the award and return to your native language.