[] How to type it out? thank you

For Chinese input methods, such as pinyin input method, just click the brackets on the Enter key.

Chinese state

English status? [? ]

You can also Ctrl+shift+M→ emoji → symbol encyclopedia → punctuation.

[] Play:

1. Press and hold the "Ctrl+ SPACE" key to open the Chinese input method.

2. Click "Emoji"-Symbol Encyclopedia on the Chinese character input method panel.

3. Then switch to Punctuation in the symbol panel.

4. Then select "full-angle left tortoise shell bracket" and "full-angle right tortoise shell bracket" and type "[]".