According to the preferable saying of Hanafi Fiqh, the time of Asr salah starts on Mislain (when the shadow of an object doubles except its original shadow). You should offer your salah according to it. What is the verse of the holy Quran that says offer salah in its first time?
Allah (Subhana Wa Ta’ala) knows Best
Darul Uloom Deoband