You Do Need power plug adapter while traveling from Nauru to Bangladesh.

Here is Why You Need An Adapter

The outlet and plug type used in Bangladesh are A, C, D, G and K and in Nauru is I. This is how they look like.

Nauru

In Nauru, outlets of type I are in use.

Type I

Bangladesh

In Bangladesh, outlets of type A, C, D, G and K are in use.

Type A

Type C

Type D

Type G

Type K