This is *Sayyid al-Istighfar* - the master dua for forgiveness. The Prophet (SAW) said whoever says it in the morning with conviction and dies before evening, will enter Jannah.
"O Allah, You are my Lord, there is no god except You. You created me and I am Your servant, and I am upon Your covenant and promise as much as I am able. I seek refuge in You from the evil of what I have done. I acknowledge Your favor upon me, and I acknowledge my sin. So forgive me, for indeed, none forgives sins except You."
Allahumma anta Rabbi, la ilaha illa anta, khalaqtani wa ana 'abduk, wa ana 'ala 'ahdika wa wa'dika ma istata't, a'udhu bika min sharri ma sana't, abu'u laka bini'matika 'alayya, wa abu'u laka bidhanbi, faghfir li, fa innahu la yaghfiru adh-dhunuba illa anta.