You Do Need power plug adapter while traveling from Andorra to Benin.

Here is Why You Need An Adapter

The outlet and plug type used in Benin are C and E and in Andorra are C and F. This is how they look like.

Andorra

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

Type C

Type F

Benin

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

Type C

Type E