While the external concrete floor assuming it is clean, dry, sound, has a damp proof membrane present and is prepared as detailed in the technical data sheet could be painted, gloss paint is not suitable to be walked on.

It has been applied to an unprepared surface.

We would recommend the paint is either sanded off prior to a suitable floor paint is applied such as Coo-Var Acrylic Floor Paint or try to remove it with Rust-Oleum Nr.1 Green Paint Stripper.