بسم الله الرحمن الرحيم
It is not valid to make intention of Isha salah in taravih. If your Isha salah is missed then offer fardh salah and then join taravih salah.
Allah knows Best!
Darul Uloom Deoband
This answer was collected from the official ifta website of Darul Uloom Deoband in India.