You Do Need power plug adapter while traveling from Côte d'Ivoire (Ivory Coast) to Papua New Guinea.

Here is Why You Need An Adapter

The outlet and plug type used in Papua New Guinea is I and in Côte d'Ivoire (Ivory Coast) are C and E. This is how they look like.

Côte d'Ivoire (Ivory Coast)

In Côte d'Ivoire (Ivory Coast), outlets of type C and E are in use.

Type C

Type E

Papua New Guinea

In Papua New Guinea, outlets of type I are in use.

Type I