Most Twitch overlay designs have been created in a way for you to add your own information where desired. To add your name to an overlay, all you need to do is create a new “text” layer in your scene and type your name in. It’s up to you to choose the font, color and size. Some overlay packages come with recommendations for matching which can be found in their readme/setup file.
How do I add my name or logo to the overlay?
flisky on August 31, 2017