Hi! It looks like you were doing everything right, except for one thing: As you can see in the error message, Prodigy raises an error in the loaders telling you the your labels aren’t a valid loader. This means you’ve accidentally passed in the labels where Prodigy expects the name of a file/API loader.
When you call prodigy.serve, the recipe arguments have to be passed in as positional arguments in order. For ner.manual, those arguments are: dataset, spacy_model, source, api, loader, label. So if you don’t want to specify an api or a loader, you’ll have to pass in None here: