Rocky Mountain Goods Atrium Grate Storm Drain Basin 3” Green - Block Leaves and Debris while Draining - Easy Install - Heavy Duty Plastic - UV Resistant - Natural Blend in Green

FYI flat grates clog pretty easy outside if there's any chance of leaves, plant debris. A raised one works much better, one like this: https://www.amazon.com/Rocky-Mountain-Goods-Atrium-Grate/dp/B0D6888Z1G Some are dome-shaped too.