أَسْتَغْفِرُ اللَّهَ الْعَظِيمَ الَّذِي لَا إِلَهَ إِلَّا هُوَ الْحَىُّ الْقَيُّوْمُ وَأَتُوبُ إِلَيْهِ

Astaghfirullaa hal-'Adheemal-ladhee laa 'ilaaha 'illaa Huwal-Hayyul-Qayyoomu wa 'atoobu 'ilayhi

I seek the forgiveness of Allah the Mighty, Whom there is none worthy of worship except Him, the Living, the Eternal, and I repent to Him. The Prophet (ﷺ) said, "Whoever says, 'I seek forgiveness from Allah, the Exalted, there is no god but He, the Ever-Living, the Everlasting, and I repent to Him', is forgiven even if he flees from the battlefield."

Reference: Sahih (Albani). Tirmidhi: 3577