Script Editor

Just in case it isn’t clear there are two parts you have to download. Download and install Visual Studio Code, and then from the Visual Code app install the ExtendScript Debugger plugin.

https://code.visualstudio.com/download

https://marketplace.visualstudio.com/items?itemName=Adobe.extendscript-debug

Also, if you are trying Visual Code on an earlier OS where ESTK is running, you have to quit ESTK. Visual Code will not work while ESTK is running—I had to quit ESTK and restart my OS in order to get it running.

The OP asks for editor 64bit

ExtendScript toolkit is a 32-bit application and with macOS 10.15 (Catalina), which supports only 64-bit applications, the ExtendScript Toolkit does not open.

Best editor for InDesign JavaScript would be Extended Tool kit.

https://www.adobe.com/devnet/scripting/estk.html

Most of the InDesign Scripters who are using javascript for InDesign (including Me) are using Extended Toolkit.

It is easy to target Adobe application.

This is best for beginner and for experts as well.

Best

Sunil

visual studio code

take a look here:

https://helpx.adobe.com/indesign/kb/indesign-and-macos-catalina.html