use-dark-mode | custom React Hook to help you implement a `` dark mode | State Container library

You can't use hooks in class component. If you want to use useDarkMode, change your component class to functional component like this:

You could give the root element a class on theme change and use css variables in root, but be class specific:

Dark_mode.jsx:

useDarkMode returns an object and not current mode in order to access the current value you need to use darkmode.value.

In your case: src={darkMode.value === "true" ? logo_font_darkMode : logo_font_lightMode}

the simulator is very likely to an actual device. For this solution, run your simulator in Xcode. After the simulator home screen shows up, go to the settings menu on your simulator, on the settings menu there is a developer menu. Click on the developer menu and you will see the dark appearance switch. If you switch that bar then all your apps will be run in dark mode. (If your app has a dark mode version).

Based on the documentation useDarkMode() returns an object with the properties like value:

value: A boolean containing the current state of dark mode.

So most probably you can try with the following:

Dark mode is available in iOS 13.0 and later