Is it permissible to donate a kidney to a patient without charge, and is it permissible to accept financial compensation if the patient insists on paying under the name of a gift?

Some scholars permit donating a kidney if there is a need, provided that doctors determine there is no danger to the donor and that the kidney is suitable for the recipient, while prohibiting the sale of organs. The donor should intend to do good and seek reward from Allah, and strive to conceal their charity. There is no harm in accepting money or a reward afterward if it was not anticipated.