From Sahih Muslim (Hadith 6850):
Abu Malik reported on the authority of his father that when a person embraced Islam, Allah's Messenger (ﷺ) used to teach him how to observe prayer and then commanded him to supplicate in these words:" O Allah, grant me pardon, have mercy upon me, direct me to the path of righteousness, grant me protection and provide me sustenance
Reference: Muslim 6850