Once you have created at least one preset, you can simply drag & drop files and folders onto the icon of the closed application. A dialog will appear allowing you to select which preset you want to apply to the files.
This is now the preferred way of automating renaming tasks. You can still create “Droplets” as in previous versions of A Better Finder Rename, but with macOS’s growing emphasis on security, more and more customers have started experiencing problems with droplets. This new Presets-based automation should allow these problems to be side-stepped.