Inside the Generative Design workspace, you have access to the Edit Model contextual environment.
Note: Here you can prepare a generative model which is a derivative of the original model and where you can make changes specific to the requirements of a generative design study. Changes you make to the generative model will not change the base model created in the Design workspace. However, any fundamental changes you make to the base model in the Design workspace will be passed along and associatively update the generative model.
If you are new to modeling, follow these tutorials to learn how to