Chapter: Concerning the athan (the call to prayer)

Status Reference : Hisn al-Muslim 26

يَدْعُو لِنَفسِهِ بَيْنَ الْأَذَانِ وَالْإِقَامَةِ فَإِنَّ الدُّعَاءَ حِينَئِذٍ لاَ يُرَدُّ

English Translation:

Between the call to prayer and the ‘Iqamah, you should supplicate Allah for yourself.
Invocation during this time is not rejected.

Reference:
At-Tirmidhi, Abu Dawud, Ahmed. See Irwaa Al-Ghalil 1/262