Does anyone know what this duaa is for?
The Prophet (ﷺ) said "The most superior way of asking for forgiveness from Allah is: 'Allahumma anta Rabbi la ilaha illa anta, Khalaqtani wa ana 'Abduka, wa ana 'ala 'ahdika wa wa'dika mastata'tu, A'udhu bika min Sharri ma sana'tu, abu'u Laka bini`matika 'alaiya, wa abu'u laka bidhanbi faghfir lee fa innahu la yaghfiru adhdhunuba illa anta." The Prophet (ﷺ) added. "If somebody recites it during the day with firm faith in it, and dies on the same day before the evening, he will be from the people of Paradise; and if somebody recites it at night with firm faith in it, and dies before the morning, he will be from the people of Paradise."
REFERENCE: Sahih al-Bukhari 6306 https://sunnah.com/bukhari:6306