Rainbow trail

Greetings, Im very grateful for your project, mean ffmpeg art school and all this scripts. This scripts make life easier:) But Im having trouble with the rainbow trail script. I just activated it, but nothing changes in the video. Im the beginner and poorly understand ffmpeg. Maybe I just doing something wrong. I did so: rainbow-trail.ps1 -s /video_files/video.mp blue 0.3 0.1 7 $true. But nothing changes. Please help me. Can you write a couple of examples of what to write down in powershell? Please. I would be very grateful to you. I`m sorry and don`t know much about computers:) My level is a common user. But i want to get into ffmpeg
Thanks