Instagram dark mode is a phone setting and not an app setting. If you were poking through the settings in the Instagram app and couldn’t find the dark theme mode, it’s because it’s not there. Additionally, turning on this setting will affect other apps besides Instagram. Apps such as Twitter, Facebook, and Google will be switched to dark mode in addition to the phone’s interface. First, you need to check if your phone and Instagram support dark mode. This setting is only available for iOS 13 and after. Next, to turn on dark mode, you need to go into your phone settings. Scroll through them until you find “Display and Brightness.” Afterward, select the Dark option.