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

Here is Why You Need An Adapter

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

El Salvador

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

Type A

Type B

Macau

In Macau, outlets of type G are in use.

Type G