Open Clipchamp and create a new project
Import your video or image
Select the clip on the timeline
Use the background removal tool if available
For images, remove the background in an external editor if needed
For videos, use a green screen or chroma key effect if supported
Adjust the transparency or opacity settings if available
Export the file in a format that supports transparency, such as PNG for images or a video format with alpha channel if supported
Save and download the exported file