The Messenger of Allah ﷺ said, "Whoever enters ihram for both Hajj and Umrah, a single tawaf suffices for them both, and he does not exit ihram until he completes his Hajj, then he exits ihram from both together."
حدثنا محرز بن سلمة حدثنا عبد العزيز بن محمد عن عبيد الله عن نافع
أن رسول الله ﷺ قال من أحرم بالحج والعمرة كفى لهما طواف واحد ولم يحل حتى يقضي حجه ويحل منهما جميعا
[Its isnad is sahih] Tirmidhi recorded it in the Hajj, chapter on what has been said that the one performing qiran makes only one tawaf, no. 948, from the hadith of Abdul-Aziz Darawardi, with the same chain, and he said, hasan gharib sahih. There is a defect, but it is not damaging.