Kingsyard Middium Heavy Duty Deck Hook - 10 inch Metal Deck Railing Hooks for Hanging Bird Feeders, Planters, Suet Baskets, Lanterns, Wind Chimes

I would get something like this to hang it from the rail. https://a.co/d/07QM1IAE Close to the ground they may avoid it if it feels like there might be predators.