You Do Need power plug adapter while traveling from Kosovo to French Guiana.

Here is Why You Need An Adapter

The outlet and plug type used in French Guiana are C, D and E and in Kosovo are C and F. This is how they look like.

Kosovo

In Kosovo, outlets of type C and F are in use.

Type C

Type F

French Guiana

In French Guiana, outlets of type C, D and E are in use.

Type C

Type D

Type E