Place mushrooms in the basket of the air fryer. Set air fryer to 350 degrees F (175 degrees C) and cook mushroom slices for 5 minutes.
Spread 1 tablespoon pesto onto the bottom half of the hoagie bun. Arrange salami slices over the pesto. Add ham and pepperoni.
Place 1 slice of cheese over the ham and pepperoni. Top with mushrooms and olives. Add remaining slice of cheese. Spread remaining tablespoon of pesto on the other half of the bun and place on top to complete the sandwich.
Place entire sandwich in the basket of the air fryer. Cook until cheese has melted and salami is crisp, about 5 minutes.