You Do Need power plug adapter while traveling from Tokelau to El Salvador.

Here is Why You Need An Adapter

The outlet and plug type used in El Salvador are A and B and in Tokelau is I. This is how they look like.

Tokelau

In Tokelau, outlets of type I are in use.

Type I

El Salvador

In El Salvador, outlets of type A and B are in use.

Type A

Type B