See the in-built help for how to run the script.
Genetic iterates through a large number of possible images in search of one that most closely matches the target. Since this can take a while it's recognised that you might want to do this across several sessions. Happily genetic can do this by saving to (& restoring from) svg files saved with the same base name as the target image. These svg files are created when the main window is closed. When resuming this pattern can be used to automatically find the created svg file, or an alternative can be specified.