Preheat oven to 375°F (190°C) and lightly grease a baking dish.
Slice zucchini lengthwise into thin strips using a mandoline or sharp knife. Lay slices on paper towels, sprinkle with salt, and let sit for 10 minutes to draw out excess moisture. Pat dry.
In a mixing bowl, combine shredded chicken, 1 cup Alfredo sauce, Italian seasoning, garlic powder, salt, and pepper.
Spread a thin layer of Alfredo sauce on the bottom of the baking dish.
Layer zucchini slices over the sauce, slightly overlapping. Top with half of the chicken mixture, followed by mozzarella cheese.
Repeat the layers: zucchini, chicken mixture, mozzarella. Finish with a final zucchini layer, remaining Alfredo sauce, mozzarella, and Parmesan cheese.
Cover with foil and bake for 25 minutes. Remove foil and bake an additional 10 minutes until cheese is bubbly and golden.
Let rest for 10 minutes before slicing and serving.