The Prophet of Allah ﷺ used to say when he broke his fast: O Allah, for Thee I have fasted, and with Thy provision I have broken my fast. (Using translation from Abū Dāʾūd 2358)
أَنَّ النَّبِيَّ ﷺ كَانَ إِذَا أَفْطَرَ قَالَ اللهُمَّ لَكَ صُمْتُ وَعَلَى رِزْقِكَ أَفْطَرْتُ