Is it obligatory to fast the missed years on behalf of the deceased who suffered from chronic diseases such as strokes, diabetes, and kidney failure, and was admitted to intensive care multiple times?

If a sick person is unable to fast and make up for it until death due to a continuous illness, then there is nothing upon him or his heirs. However, if he was able to make up for it but neglected to do so, he must feed a poor person for each day. And if the illness is incurable, then his duty is to feed a poor person for each day, and this should be taken from his estate if he did not do so.