Webpack tips: How to output multiple html

I'm developping a figma plugin with multiple UIs, so I needed to be able to do so. This requires to use HtmlWebpackPlugin for Webpack. So here it is in case you needed it also, this will save you a few hours of research maybe also I'm using grafcet.online (kind of scratch for professional programming) visual component or DSL (Domain Specific Langage) to avoid stupid configuration error ;)