Add any mesh object (a plane is enough; its geometry is ignored), add a Geometry Nodes modifier and choose Tidebone Stucco Cornice Lite. Inputs: Profile, Length, Profile Size, Projection, Mitre Left, Mitre Right, Ornament (None, Dentil), Ornament Size, Ornament Depth, Plaster, Ornament Material. The cornice stands out of the wall plane towards −Y; the origin is the centre of the run at the bottom edge of the profile. Units: metres. See README.md.