You Do Need power plug adapter while traveling from Fiji to Central African Republic.

Here is Why You Need An Adapter

The outlet and plug type used in Central African Republic are C and E and in Fiji is I. This is how they look like.

Fiji

In Fiji, outlets of type I are in use.

Type I

Central African Republic

In Central African Republic, outlets of type C and E are in use.

Type C

Type E