The page header reads Configuration: Global or Configuration: <kitchen name> depending on the kitchen selected in the kitchen dropdown in the admin top bar. Nearly all Theme and Marketing settings are global only: they apply to every location and are hidden when a specific kitchen is selected. The exceptions in this area are Show on Header Menu and Show on Footer (Theme > Kitchen), which can be set differently per kitchen location. If you cannot see a Theme or Marketing tab, switch back to the Global configuration.