In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
In this fatwa:
Answering your question, The Fatwa Center at Islamweb, states:
Whoever fulfills the requirements of the obligation of fasting, i.e., being of age (i.e. having attained puberty), being sane, conscious and healthy, and yet intentionally breaks fasting on a Ramadan day, two things become due on him/her: first, to repent from that sin and second, to make up for the broken or missed fasts.
If these fasts were not made up for until the next Ramadan had come, it becomes incumbent, in addition to making up for the fast, that a poor person must be given food, for each day on which fast was not observed.
However; in case of ignorance of the prohibition of delaying makeup fast until the next Ramadan comes, no expiation will be due.
It is preferable to offer food in coincidence with makeup fasting, i.e. to fast a day and then offer the expiatory amount of food for one day, and so on. Nevertheless, offering expiatory food can be done before or after observing a makeup fast.
Hence, the questioner can give expiatory food after observing makeup fast for those days.
Almighty Allah knows best.