How to set DarkMode in Twitter Desktop
On the twitter homepage, go to the left-side panel and click on “more”.
Click on display
You can change the font size, color and background color as your preference from the window.
How to set dark mode on twitter mobile
Open the Twitter app on your android or iPhone
Tap on your display picture on the upper left-hand corner to open the lefthand menu. On the menu tap on “Settings and Privacy”
On the Settings and Privacy window, on the ‘General‘ section click on ‘display and sound‘
Use the Display and sound menu to find the dark mode on/off feature. You can set up it to work automatically as well