Just convert your logo into 3d model and place it on the stamp head.

Make sure that the logo is mirrored.

Tips:
- make your logo simple as possible
- reduce small enclosed space within the logo as it may chip the soap
- trace and deburr the logo for better stamp result
- use .2 nozzle for the stamp head for better logo print result
- change filament color before the logo surface to give it accent
- use variable height and speed, I recommend .12 layer height and slow speed for the threads