This procedure is classified as a "Bottom" procedure.

A radial forearm free flap (RFFF) involves taking the skin, fat, nerves, arteries, and veins from your wrist to about halfway up your forearm to create the penis. Typically, the surgeon will use your non-dominant hand so that you are better able to recover post-operatively with minimal effect on dominant hand function. Source: https://www.hopkinsmedicine.org/center-transgender-health/services-appointments/faq/phalloplasty