Is it permissible to pay zakat in lieu of the missed Ramadan fasts due to menstruation, and if so, how; and if not, is there an expiation for that, knowing that I missed three years of fasting due to a state of severe fainting and exhaustion?

A woman who intentionally breaks her fast in Ramadan has committed a grave sin and must repent. If she delays making up the days of her menstrual period until the next Ramadan begins, without a valid excuse, she has sinned. In this case, she must make up the fasts and feed one poor person for each day, unless she was unaware of the prohibition against delaying. If she is unable to make up the fasts due to an illness from which recovery is not expected, she must feed one poor person for each day. However, if she is capable of making up the fasts, or if her illness is one from which recovery is expected, then feeding the poor does not suffice for making up the fasts.