What is the expiation for adultery after sincere repentance?

Adultery is a grave sin and an abominable act. Allah has threatened those who commit it with torment and disgrace in this world and the Hereafter. However, Allah accepts sincere repentance and transforms evil deeds into good ones for those who repent, believe, and perform righteous deeds. For sincere repentance:

1. Feeling remorse and shame before Allah for committing the sin.

2. Having a sincere resolve not to return to the sin, by avoiding its causes and precursors, adhering to the prescribed hijab, and refraining from private seclusion with non-mahram men.

3. Performing many righteous deeds, and sincerely seeking refuge in Allah and His help, to request protection from error.