You Do Need power plug adapter while traveling from Benin to Myanmar (Burma).

Here is Why You Need An Adapter

The outlet and plug type used in Myanmar (Burma) are A, C, D, G and I and in Benin are C and E. This is how they look like.

Benin

In Benin, outlets of type C and E are in use.

Type C

Type E

Myanmar (Burma)

In Myanmar (Burma), outlets of type A, C, D, G and I are in use.

Type A

Type C

Type D

Type G

Type I