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]