If you finish the Dua early, simply recite Salawat (Durood) or Istighfar (Astaghfirullah) until the Imam stands up.
“Subhanal Malikil Quddus, Subhanal Malikil Quddus, Subhanal Malikil Quddus…” followed by salawat upon the Prophet ﷺ and a longer dua asking for forgiveness, mercy, and entry into Jannah. Taraweeh Dua Pdf
In fact, Islamic scholars and websites like IslamQA explicitly state there is no basis in the Sunnah for reciting a specific dua between the salams of Taraweeh prayer. To consider this dua an obligatory part of the prayer would be an innovation (bid'ah), which is strictly prohibited in Islam. If you finish the Dua early, simply recite
"Exalted is the Possessor of the hidden and the manifest kingdom. Exalted is the Possessor of Might, Greatness, Reverence, Power, Pride, and Majesty. Exalted is the King, the Living, who neither sleeps nor dies. Most Perfect, Most Holy, our Lord and the Lord of the angels and the Spirit. O Allah, save us from the fire; O Protector, O Protector, O Protector." Essential Features of a Taraweeh Dua PDF To consider this dua an obligatory part of