If you are a church member, it includes the elders of the church. For all of us, this includes authorities such as presidents, senators, representatives, judges, governors, policemen, etc. Paul does not say in this passage. God has ordained authority to keep law and order in His world. It is a protective agency.
Government exists to protect good citizens from evil by punishing lawbreakers.
Government is God's servant for your good, Paul says. I know that under our present administration, some people have gotten quite cynical and critical of government as if government itself was evil. The thing that is wrong with government usually is found in the lives of its administrators. Yet even bad government is better than no government. In the history of the world, it has been a rare mercy when a nation had a godly ruler.