Clean the mushrooms with a damp paper towel. Gently twist and remove the stems. Using a small spoon, carefully scrape out the dark gills to create a wider cavity for the filling. Pat the mushroom caps completely dry inside and out.
In a medium bowl, combine the crab meat, softened cream cheese, parmesan cheese, mayonnaise, sliced green onion, minced garlic, lemon juice, Old Bay seasoning, salt, and black pepper. Fold gently until everything is well mixed, being careful not to break up the crab too much. You want nice visible pieces throughout.
Generously fill each mushroom cap with the crab mixture, mounding it slightly above the rim.
In a small bowl, toss the panko breadcrumbs with the melted butter until evenly coated. Sprinkle the buttered breadcrumbs over each stuffed mushroom, pressing gently so they stick to the filling.
Preheat the air fryer to 350 degrees F for 2 minutes. Arrange the stuffed mushrooms in a single layer in the air fryer basket, leaving space between each one for air circulation.
Air fry for 8 to 10 minutes, until the mushrooms are tender, the crab filling is heated through, and the breadcrumb topping is golden brown and crispy.
Let cool for 2 minutes, then transfer to a serving plate. Garnish with fresh snipped chives and serve with lemon wedges on the side.