Latex paint was sprayed on a rusted roof drip edge and rust is showing through. Can I spray this on top of it or do I have to remove the latex paint?

Thanks for reaching out. Before applying Rust-Oleum Stops Rust Protective Enamel Spray Paint over rusty metal painted with latex paint, use a wire brush or sand paper to remove any loose rust and peeling paint. Next, prime the surface with Rust-Oleum Rusty Metal Primer, the primer can then be top coated with Stops Rust Flat Black. - Rust-Oleum Product Support 6