Having images with a transparent background will enable you to create more advanced designs. Channable does not yet offer the option to remove the background from images. However, there exist many tools specialized in removing the background from images.
If you choose to use one of these tools, you can import the resulting images into Channable by hosting them online and including the URL in your product feed or use an additional import.
Below is a selection of the available tools. They all offer a paid option to remove backgrounds in bulk and/or via an API. It requires some technical knowledge to set this up.