Is Zakat al-Fitr obligatory for someone whom God guided on the last day of Ramadan, so he prayed and fasted, and what are the consequences if he does not pay it?

Whoever embraced Islam before sunset on the last day of Ramadan is obligated to pay Zakat al-Fitr, based on the saying of Ibn Umar, may Allah be pleased with them both: "The Messenger of Allah, peace and blessings be upon him, enjoined Zakat al-Fitr at the end of Ramadan upon the people, a 'sa' of dates or a 'sa' of barley, for every free person or slave, male or female, among the Muslims." As for whoever embraced Islam after sunset on the last day of Ramadan, Zakat al-Fitr is not obligatory upon them.