Your svg (which can contain either a bitmap or a vector, or both) consists of a bitmap (raster image) only, which can only be engraved in the Glowforge. To cut it out you need a vector cut line. One way to generate the cut line would be to print the image, place the printout in the center of your Glowforge bed, and use the Glowforge Trace function. Consult the online manual for instructions on how to do this.
Most people use a vector graphics program like Inkscape (free) or Illustrator ($$$) to generate a cut line using the software’s auto Trace function. Here’s a reference for how to do it in Inkscape: