I use external editor to write code, how to complete automatically.

I use external editor to write code, how to automatically code.

Do you mean using autocomplete? That's a feature of the editor, so it depends entirely on the features of whichever editor you're using.

Note Construct's built-in editor has Construct-specific autocomplete based on its own APIs, such as listing runtime methods after typing runtime.. Other editors won't be able to do that, because they aren't specially designed for Construct's APIs.