Answered by Shaykh Abu Usamah
When offering Tarawih on one’s own can you do 4 raka’ahs or do they have to be in twos?
Tarawih salah prayed in congregation or individually must be offered in cycles of two. It is makruh (disliked) to intentionally offer it in cycles of four although it will be valid.
See Al-Tahtawi `ala Maraqi al-Falah p 336 and Radd al-Muhtar v2 p48