Lightweight backend modules

Hello I am trying to create backend module using the instructions from … d-modules/ And I am totally confused. What is a createSimpleModule function? There is no function with the same name anywhere in your code. Where can I find the postmessage-api.js file? Is this documentation outdated? Any other ways how can I do the same?

Hello, do you already use Shopware 5.1? This feature is completely new and can only be used in 5.1.0 and not the previous versions. Moritz