Anas (May Allah be pleased with him) reported:
The Messenger of Allah (ﷺ) said: "The supplication made between the Adhan and the Iqamah is never rejected."[Abu Dawud and At-Tirmidhi]. (ES)
App reference (ES): Book 9, Hadith 51 (ES)
English reference (ES): Book 9, Hadith 1041 (ES)
Arabic reference (ES): Book 9, Hadith 1043 (ES)