The spiffs_rom contains a Spiffs FS, created at build time with the contents of the "web" subdirectory of the project. As that non-existing here the FS will hold no files. This FS can/should be updated to the esp too.
Suggest you move to SmingRTOS, there is no Basic_Updater as use rBoot for firmware updates.
Take basic_rboot as the start, that has firmware update and spiffs usage/flashing