Substitutes orteam officials

Who is not allowed on the pitch during a football/soccer match?

If a substitute, substituted player, team official or player who has gone off the pitch with an injury or to change kit, etc. enters the pitch without permission and interferes with the ball when it is going into their team’s goal but it still goes in, the goal can be awarded if the interference did not stop a defender or the goalkeeper from playing the ball.

What happens if…