Put a shallow bin or tray on the floor in front of the couch. Put a small handful of droppable objects (blocks, pom-poms, dry pasta) on the couch within the child's reach.
Pick up one block. Hold it over the edge of the couch. Let it drop into the tray. Don't say anything.
This is the activity 2-year-olds invent themselves with food off the highchair. Giving it a designated tray turns it from "frustrating" to "the work." They will drop everything, gather it, drop it again.
Replace blocks with cotton balls (float drop), then with dry pasta (loud drop). Different objects = different drops = same schema, new feedback.