How is the prostration of forgetfulness (sujood as-sahw) performed for a missing rak'ah in prayer, and does it differ if the missing rak'ah is the second one?

The prostration of forgetfulness (sujood al-sahw) consists of two prostrations, with a sitting posture between them, followed by the salutation (taslim (definition)). If the worshiper makes the salutation before completing the prayer and then performs the forgotten rak'ah, the prostration of forgetfulness should be done before the salutation. The prostration of forgetfulness does not replace the pillars of the prayer. Therefore, whoever forgets a pillar must perform it, then prostrate for forgetfulness before the salutation. However, if one prostrates after the salutation, their prayer is still valid.