No, you do not have to retreat before using force in self-defense. Depending on your state’s laws, you may be able to use deadly force if the robber is threatening you with a weapon or if they are committing a violent felony. However, it is important to remember that the law does not require you to retreat and that the use of lethal force should always be a last resort.
It is also important to remember that while self-defense is legally justified in certain circumstances, it can still have serious legal consequences. It is best to contact your local police department and/or consult an attorney before taking any action against a potential robber. They can provide more information about the specific laws in your area and help ensure that any action taken is within the bounds of the law.