Q: Is performing two Rak`ahs (unit of Prayer) behind Maqam Ibrahim (the Station of Ibrahim) obligatory for every Tawaf (circumambulation around the Ka`bah)? What is the ruling on forgetting them?

A: It is not obligatory to perform two Rak`ahs behind Maqam Ibrahim. It will be sufficient to perform them at any place in Al-Haram (the Sacred Mosque in Makkah). But there will be no blame on a person who forgets them because they are supererogatory acts of worship, but not an obligation. May Allaah grant us success!

[Fataawa Shaykh Ibn Baaz - Alifta.net]