AR advantage?

[wardtc]

How would you guys handle this...?

On a counter attack from the other end of the field, the ball goes deep into your corner. You follow it and the players down, the Center is still coming up the field when the defender fouls the attacker (outside the box). The attacker regains control of the ball. Clearly an advantage call.

Do you raise the flag for the foul, or apply advantage. If you apply advantage, how do you signal that?