Overlaying the superimposed video backdrop for your TikTok green screen video will include many steps which you need to follow when you use the still image. Again, you may want to click on the plus sign to create a new video and then click on the effects icon that is adjacent to the record button. Instead of choosing the first option this time you may want to click on the green screen video option that you can differentiate by the play symbol. Next the app will bring up the photo library from which you may choose the video that you want to use as your background and add any effects, filters, or sound effects that you want to include.