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

Here is Why You Need An Adapter

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

French Guiana

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

Type C

Type D

Type E

Chile

In Chile, outlets of type C and L are in use.

Type C

Type L