What is the ruling on praying for the death of a child afflicted with autism, especially with the worsening of his condition and the difficulty of caring for him?

It is not permissible to supplicate against oneself or one's children, because the Prophet, peace and blessings be upon him, forbade that, saying: "Do not supplicate against yourselves, nor supplicate against your children, nor supplicate against your possessions. Do not coincide with a moment from Allah in which a request for a gift is made and He answers you." One should rather supplicate for them for healing, guidance, and goodness, for Allah Almighty is capable of guiding them. One can also seek assistance from a mahram to play a role in preventing harm.