In theory you could. The body and especially the brain are incredibly adaptive, and we already know how to attach limbs with pretty high success rates.
So in theory you could either surgically fashion a tail from other body parts, or (still super early tech with mostly failed attempts) decellulise an animal tail.
Once you have a tail you can just attach it to some veins, arteries, nerves and muscles. After a healing period you will start physical therapy and slowly learn how to control it.
In theory you could. The body and especially the brain are incredibly adaptive, and we already know how to attach limbs with pretty high success rates.
So in theory you could either surgically fashion a tail from other body parts, or (still super early tech with mostly failed attempts) decellulise an animal tail.
Once you have a tail you can just attach it to some veins, arteries, nerves and muscles. After a healing period you will start physical therapy and slowly learn how to control it.