Thanks to Gunnar Hjalmarsson, just adding on to his answer I have made a descriptive post here.

To get Chinese language IME on Ubuntu Server 20.04 LTS

1. Install ibus-libpinyin -

sudo apt install ibus-libpinyin

2. Go to Settings > Region and Language > click on “+” and add Chinese(Pinyin) to the list
   

   
   



3. Click on setting gear symbol here and it will show “preferences”
   
   
   

   
   



4. Use command “ibus-setup” and it will start ibus-daemon
   

   
   

Set these environment variables to keep ibus-daemon running

It will open ibus settings –

In input-method add “Chinese Intelligent Pinyin” and remove “Chinese Pinyin” if any

5. Switch to Chinese language using “super(windows)+space” key, for chinese pinyin it will show IME
   

   
   



6. If you get “Invalid UTF-8” error while typing in Chinese then use command –

   
   

ibus-daemon -drx