How do you masturbate using a penis pump

I know it is possible to ejaculate using a penis pump but I just can’t do it, is there a technique?

I would think it involves a less-than-maximum vacuum so the tube/cylinder can be moved up and down on the shaft. That’s about the only way I can see it working.

Well you could google “prostate orgasm”, and practice that, while remaining under vacuum.

If you are packing the tube, you can try holding a strong vibrator on the outside of the tube. It is not easy coming inside the cylinder however.