You Do Need power plug adapter while traveling from Congo to Barbados.

Here is Why You Need An Adapter

The outlet and plug type used in Barbados are A and B and in Congo are C, D and E. This is how they look like.

Congo

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

Type C

Type D

Type E

Barbados

In Barbados, outlets of type A and B are in use.

Type A

Type B