How can one make up missed obligatory prayers during congregational Tarawih prayers?

Summary

A person who owes missed obligatory prayers may make them up behind the Tarawih imam to gain the reward of praying in congregation. In the Shafi'i school, it is valid for a follower intending a make-up prayer to follow an imam performing a voluntary prayer, even though their intentions differ. For prayers of three or four rakaat, the follower stands to complete the remaining rakaat after the imam gives the salam, and it is preferable to complete them alone. All missed prayers, whether due to a valid excuse or not, must be made up, and it is recommended to follow the order of the prayer times.

Written in our own words from the original fatwa — check the source before acting on it.