What is the method of repentance for committing Zina (fornication/adultery), knowing that the perpetrator is observant of their prayers and has knowledge of the religion?

The aforementioned act, even if it is not zina (fornication/adultery) or liwat (sodomy) that necessitates a hadd punishment, is an مقدمة (introduction) to the indecency that Allah Almighty has forbidden, as He says: "And do not approach unlawful sexual intercourse. Indeed, it is ever an indecency and is evil as a way." (Quran 17:32) The door of repentance is open for sinners as long as the sun has not risen from the West or death is not witnessed. Allah Almighty accepts the repentance of His servant as long as the death rattle has not begun. The sincere penitent's evil deeds are transformed into good deeds if he repents, believes, and does righteous deeds, and good deeds remove evil deeds. Allah loves repentance and rejoices in it. Therefore, the sinner must achieve a sincere repentance by regretting the sins, abandoning them, resolving not to return to them, and rectifying any injustices.