You Do Need power plug adapter while traveling from Bolivia to Namibia.

Here is Why You Need An Adapter

The outlet and plug type used in Namibia are D and M and in Bolivia are A and C. This is how they look like.

Bolivia

In Bolivia, outlets of type A and C are in use.

Type A

Type C

Namibia

In Namibia, outlets of type D and M are in use.

Type D

Type M