The execution of protestors is ordered by Koran

An Ayatollah answered someone's question regarding using life imprisonment instead of death penalty. Listen to what he says:

Question: The death penalty, which aggravates the desire for revenge, can life imprisonment be used instead?

Answer: Islam believes that it does not have that inhibition.

The Qur'an says that a warrior must be killed severely.

I would also like to point out one thing here, so the prison from whose pocket? On whose account?
If he is imprisoned, it has costs. Water, electricity, security, gas, rest and bed. Islam does not believe in that.

Between you and God, if you repent, you will be happy in the Day of Resurrection, but he must be executed and the society must be relieved.