My guess is that the layers you are adding just state the function name instead of calling the function with the appropriate inputs to specify how you want it to work. The instructions in the notebook are not as helpful as one might wish, but here’s a thread that gives some concrete instructions for how to use the Keras Sequential and Functional APIs. For the “happy model” section, we’re using the Sequential API and then in the second part of this assignment we use the Functional API.