The Flipping locomotion is a hand locomotion; a Flipper can be enabled on each hand of the player via locomotions cycling. As with any other hand locomotion, this must be done for each hand for which you want its locomotion to become active.
Upon input, a Flipper will flip the player. Flipping will optionally flip the direction of gravity at the same time. If the player is on a thin surface, flipping will put the player on the surface's opposite facing. This is an effect of physics, not Terrain Response.