Centrifugal force:

The centripetal force pulls the object towards the center of the circle. As a reaction, another force appears at the center of the circle which is equal in magnitude to the centripetal force but opposite in direction. This outward reaction is called centrifugal force

According to Newton's third law of motion, there exists a reaction to this centripetal force. The centripetal reaction that pulls the string outward is sometimes called the centrifugal force

Example:

If we whirl a piece of stone tied to one end of a string, the stone is pulled inwards due to the centripetal force transmitted to it through the string. As a reaction, the stone pulls our hand outwards, and this outward reaction force on our hand is the centrifugal force.

DO YOU KNOW?

While the coaster cars move around the loop, the track provides centripetal force preventing them to move away from the circle.