You Do Need power plug adapter while traveling from Botswana to United Kingdom (UK).

Here is Why You Need An Adapter

The outlet and plug type used in United Kingdom (UK) is G and in Botswana are D and G. This is how they look like.

Botswana

In Botswana, outlets of type D and G are in use.

Type D

Type G

United Kingdom (UK)

In United Kingdom (UK), outlets of type G are in use.

Type G