Prepare the oven and preheat it to 400 degrees F. Also, prepare a baking tray by lining it with parchment paper or aluminum foil , then grease the paper with oil spray
Transfer the potatoes to a large bowl, drizzle olive oil, add lemon zest and sprinkle Italian seasoning, garlic powder, salt, and pepper; drizzle lemon juice and mix everything using hand until potatoes are evenly coated.
Spread the coated potatoes on the prepared baking tray, place in the oven and bake for 30 minutes.
Meanwhile, make 3 equal fish fillets and pat dry using a paper towel.
To prepare the marinade, pour maple syrup into a small bowl, add lemon juice and zest, chili flakes, Italian seasoning, garlic powder, paprika, oil, salt and pepper, and mix well. Save some of the marinade for later.
Apply the marinade to the fish fillet using a brush and leave it to rest for 5 to 10 minutes.
Meanwhile, place the zucchini in a large bowl, season with pepper and salt, add lemon zest, drizzle red wine vinegar and oil, and toss gently to make an even coating.
After 30 minutes, remove the potatoes from the oven, shift them to one half of the tray, add 3 salmon fillets in the center of the tray, and apply oil spray on the fish.
Return to the oven and bake for another 10 minutes. Then remove from oven and spread coated zucchini in the remaining space of the baking tray and apply oil spray on them.
Return to the oven and bake for 5 more minutes. Add butter to the remaining marinade and place in the microwave oven for 2 minutes until the butter melts.
Take the baking tray out of the oven, apply the marinade on the fish and veggies using a brush and serve on the serving plate.