Is it permissible to offer expiation for days of fasting missed due to menstruation, given the inability to make them up by fasting because of continuous work circumstances?

A woman must make up for the days of fasting she missed in Ramadan due to menstruation, based on the saying of Aisha (may Allah be pleased with her): "We were commanded to make up for the fast." Expiation (kaffarah) does not suffice for making up the fast (qadaa'), and work is not an excuse for not fasting. The missed days can be made up during weekly or annual holidays, and consecutive making up is not required.