What should one who wronged another by raising his voice at him, and did not apologize to him, do, especially if he fears that the person has not forgiven him?

Since the questioner admits to having wronged the worker unjustly, she must return to him and apologize or ask for his forgiveness, for the Prophet, peace and blessings be upon him, said: "Whoever has wronged his brother concerning his honor or anything else, let him seek his forgiveness today before there will be no Dinar or Dirham. If he has good deeds, some of them will be taken proportionate to his injustice. And if he has no good deeds, then some of his brother's evil deeds will be taken and put on him." If she cannot find him, or if an obstacle prevents her from doing so, then she should seek forgiveness from Allah the Almighty, and seek forgiveness for that worker and supplicate for him, and turn to Allah to bear this responsibility for her on the Day of Resurrection.