This page accepts a yaml file containing generator options. You can find a documented example at playerSettings.yaml. This file can be saved as .yaml, edited to your liking and then supplied to the generator. You can also upload a .zip with multiple YAMLs. A proper menu is in the works. You can go to Race Mode to create a game without spoiler log and with encryption.
After generation is complete, you will have the option to download a patch file. This patch file can be opened with the Client to create a rom file. In-Browser patching will come.