If Ramadan arrives and someone cannot fast because they are elderly or chronically ill with no hope of recovery, then fasting is not required for them. Instead, they should feed one poor person for each missed day.
They can do this in either of these ways:
Give a poor person half a sā‘ of staple food (such as rice), which is roughly about 1.5 kg, for each day, or
Prepare a meal and invite poor people to eat.