Preheat a smoker to 250°F. Use a mild wood such as apple or cherry for a gentle smoke flavor.
In a large bowl, combine the ground turkey, grated zucchini, egg, Parmesan, onion, Dijon mustard, garlic powder, salt, black pepper, and smoked paprika. Mix gently until everything is evenly combined. Avoid overmixing, which can make the meatloaf dense.
Shape the mixture into a compact loaf on a piece of smoker-safe foil or in a small smoker-safe pan. Leave space around the loaf so the smoke can circulate.
Place the meatloaf in the smoker and cook until its center reaches 165°F, checking with an instant-read thermometer. Transfer it to a plate and let it rest for 10 minutes before slicing.
While the meatloaf rests, stir together the mayonnaise, lemon juice, lemon zest, parsley, and dill in a small bowl. Serve the aioli alongside the sliced meatloaf or spoon a little over each portion.