Does your plugin appear in the "New recipe" menu ?
* If it does, then to make it also appear in the dataset actions, you need to add in the recipe.json file a line like:
Where "main" must be replaced by the name of the input role in which the "current" dataset will go
* If it does not, then it means your plugin does not work properly, probably because of a parsing error somewhere. In the dev section, do you see warnings about components not loaded ? You can also check the backend.log file for errors loading that plugin