How can a questioner return money to a person whose car he hit, when he has no information about him?

The one at fault in a car accident must guarantee the value of the damage he caused, and he must repent for lying to the owner of the damaged car. If he had reached an agreement with him on a specific amount, he must strive to reach him; if he does not find him, he must give the amount in charity on his behalf. If there was no agreement, he must give in charity what he believes will clear his conscience.