On the website, open the Account Drawer (seen below)
Then open the "Display theme" menu in order to select your preference. In this menu, you can choose between dark mode, light mode, or stick with the default settings of your device or computer.
- "Match device" matches your phone or computer's setting
On the mobile app, open the “My Post” tab, and then click the settings gear icon in the top right corner of the screen, as shown below. In the settings menu, you can select dark mode, light mode or default to your mobile device’s system settings.