how to Draw Line Renderer with Polygon collider in unity2D?
LineRenderer and PolygonCollider2D are not related. LineRenderer can go in full 3D space, whereas PolygonCollider2D operates in a 2D context.
You would need to write a function to marshal the points you put into the LineRenderer so they are 2D points and construct a properly-filled out PolygonCollider2D object to match your LineRenderer.