You Do Need power plug adapter while traveling from São Tomé and Príncipe to Argentina.

Here is Why You Need An Adapter

The outlet and plug type used in Argentina are C and I and in São Tomé and Príncipe are C and F. This is how they look like.

In São Tomé and Príncipe, outlets of type C and F are in use.

Type C

Type F

In Argentina, outlets of type C and I are in use.

Type C

Type I

I am from

going to