Refer to figures.
To turn the main rotor the engine must exert a turning force or “torque” on the main rotor shaft.

According to the Newton’s 3rd Law:

Every action must have an equal and opposite reaction. So, the effect of applying torque to the main rotor shaft, is an equal and opposite rotation of the fuselage.

In a hover, the main rotor generates torque that tries to spin the helicopter in the opposite direction of its main rotor. To counteract this torque and maintain heading, helicopters use the tail rotor, producing a horizontal tail rotor thrust, which is controlled by applying the corresponding anti-torque (yaw) pedal.

For a clockwise helicopter, the horizontal tail rotor thrust is to the left, to counteract the torque effect. So, the Pilot should apply right pedal to maintain heading preventing the helicopter spinning counterclockwise.

During a turn in the same direction as the main rotor's rotation, the torque generated by both the main rotor and the turn itself intensifies. As a result, the tail rotor must work harder to counteract this combined torque, leading to increased power requirements. Thus, a right pedal would increase the power required.

Conversely, when the helicopter turns in the opposite direction of the main rotor's rotation, the main rotor's torque aids the tail rotor in countering the turn. This reduces the tail rotor's workload, resulting in decreased power demands because it doesn't need to exert as much force to maintain control.

The tail rotor also provides the directional control for the helicopter during hovering and engine power changes with reference to the vertical or normal (yaw) axis, which runs vertically through the fuselage. When right pedal is applied, then the helicopter yaws to the same direction, right. When left pedal is applied, then the helicopter yaws to the opposite direction, left, with reference to the vertical (yaw) axis.