I looked all over the place for how to configure the antlr4 plugin for IntelliJ IDEA. But I can\'t find anything. I was only able to install the plugin. If I add .g4 files manua
Have you looked at the GitHub project page, IntelliJ Idea Plugin for ANTLR v4? You will find many screenshots with explanations.
Directly install from here: https://plugins.jetbrains.com/plugin/7358-antlr-v4-grammar-plugin/
You should also see tool windows such as the preview window.