What is the ruling for someone who broke their fast in Ramadan out of ignorance that this action invalidates the fast, and does this entail expiation (kaffarah) or merely making up the day?

Whoever breaks their fast out of ignorance, their fast is not invalidated, nor is expiation (kaffarah) obligatory upon them, because the divine command is not established until it is conveyed. Thus, the ignorant person is excused due to their ignorance. However, it is more cautious to make up for that day to avoid disagreement among scholars.