Am I obliged to offer expiation for delaying the making up of (fasting) days from previous Ramadans due to ignorance of its obligation, and how is it to be offered if it becomes obligatory, considering my limited means and lack of knowledge of the poor?

If one delays making up the days they missed in Ramadan until the next Ramadan without a valid excuse, they must, in addition to making up the fasts, pay expiation for each day, which is a mudd (a measure) of food. Ignorance of the obligation of expiation is not an excuse, as long as they knew it was forbidden to delay making up the fasts. If they cannot find what to give for the expiation, it is waived for them, according to the more preponderant opinion among scholars. The expiation can be given to a trustworthy charitable organization if there are no poor people in the country of the one paying the zakat.