What do Qur'an and Sunnah say about giving Azaan through the speakers? Is it allowed? Jazak Allah

Praise be to Allah, the Lord of the Worlds; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.

There is no harm in giving Azan with speakers, and it is even demanded for two things:

Firstly, in doing so, a greater number of people are informed about the time of the prayer, and the Azan is legislated for such a thing.  That’s why the Prophet (Sallallahu Alaihi wa Sallam) had chosen the companion who had the best and strong voice to call for the prayer.

The caller to the prayer at that time had to climb up a high place in order to inform the greatest number of people.

Secondly, the caller to the prayer gets a great reward.  The Prophet (Sallallahu Alaihi wa Sallam) said to some of his companions: “If you were shepherding your cattle, or in a countryside, and were to call for the prayer, raise your voice with the call.  Any human being or Jinn who hears it will be a witness for that on the Day of Judgement”.

Allah knows best.