You Do Need power plug adapter while traveling from Fiji to Senegal.

Here is Why You Need An Adapter

The outlet and plug type used in Senegal are C, D, E and K and in Fiji is I. This is how they look like.

Fiji

In Fiji, outlets of type I are in use.

Type I

Senegal

In Senegal, outlets of type C, D, E and K are in use.

Type C

Type D

Type E

Type K