If a block is kept in an accelerating elevator then how does the pseudo force generated act and on which body does it act?

In this case we observe the block from the elevator itself.Which forces are acting on it?

(1)mg downwards

(2)Normal reaction upwards.

And the block is at rest.So mg=normal reaction

Now observe it from the ground frame.

Forces acting on it are:

(1)mg downwards

(2)Normal reaction upwards.

And the block is accelerating upwards.So N-mg=ma

You can see the difference bewteen the two equations obtained.This force ma is the psuedo force.This acts on the block only in the direction opposite to the direction of motion of the elevator.

the psuedo force acts on the bodies that are stationary in the accelerator and it acts in the direction  opposite to the motion of the accelerator