Abu Khadeejah 'Abdul-Waahid (hafidhahullah Ta'ala) was asked about how missed Fajr prayer is to be made up during a Question & Answer Panel Session with Abdulilah Lahmami and Abu Mu’ādh Taqweem Aslam (hafidhumullah Ta'ala)
He (hafidhahullah Ta'ala) gave the following answer:
Abu Hurairah (رضي الله عنه) narrated that the Prophet ﷺ said: "Whoever invites to guidance will be rewarded like those who follow him in the guidance are rewarded, and that will not decrease the reward of those who have followed him." [Collected by Imām Muslim]