You Do Need power plug adapter while traveling from Guyana to South Korea.

Here is Why You Need An Adapter

The outlet and plug type used in South Korea is F and in Guyana are A, B, D and G. This is how they look like.

Guyana

In Guyana, outlets of type A, B, D and G are in use.

Type A

Type B

Type D

Type G

South Korea

In South Korea, outlets of type F are in use.

Type F