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]. (JA)
App reference (JA): Book 9, Hadith 51 (JA)
English reference (JA): Book 9, Hadith 1041 (JA)
Arabic reference (JA): Book 9, Hadith 1043 (JA)