Is it permissible for a wife to seek divorce from her husband due to his lack of sperm and weak chances of conception, and must she return the dowry and gold to the husband after divorce in this case?

A woman is permitted to seek a divorce if there is harm and injury, based on the Prophet's (peace be upon him) saying: "No woman should ask her husband for a divorce without a valid reason, lest she lose the scent of Paradise," and his saying: "Any woman who asks her husband for a divorce without a fault, the scent of Paradise will be forbidden to her." If the husband agrees to the divorce, the woman is entitled to all her rights. If he refuses, she can seek khul' from him by waiving her mahr (dowry) or a portion of it.