Assalamu Alaikum Wa Rahmatullah Wa Barakatuh
Allahumma inni laka sumtu, wa bika aamantu, wa 'alayka tawakkaltu, wa 'ala rizqika aftartu.
Meaning: "O Allah! I fasted for You, I believe in You, I put my trust in You, and with Your provision, I break my fast.