Arduino IDE 2.0 introduces an autocomplete feature for writing your code. Follow these steps to enable the feature.
Open the IDE.
Open the Preferences window.
File > Preferences.
Arduino > Preferences
Check the Editor Quick Suggestions box and click OK to save.
Note that there is a bug (on version 2.0.0-beta.11 and earlier) that causes the box to appear unchecked when the preference window is opened, even if the feature is enabled.
- Autocomplete is now enabled: