You Do Need power plug adapter while traveling from Namibia to East Timor (Timor-Leste).

Here is Why You Need An Adapter

The outlet and plug type used in East Timor (Timor-Leste) are C, E, F and I and in Namibia are D and M. This is how they look like.

Namibia

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

Type D

Type M

East Timor (Timor-Leste)

In East Timor (Timor-Leste), outlets of type C, E, F and I are in use.

Type C

Type E

Type F

Type I