You Do Need power plug adapter while traveling from Belarus to Laos.

Here is Why You Need An Adapter

The outlet and plug type used in Laos are A, B, C, E and F and in Belarus are C and F. This is how they look like.

Belarus

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

Type C

Type F

Laos

In Laos, outlets of type A, B, C, E and F are in use.

Type A

Type B

Type C

Type E

Type F