

So plastic sprockets do not need any type of lubrication? Do you only need to grease the points I marked with squares in the photo I uploaded now? Thank you.
The gears are not greased, only their respectful axes in that mechanism and when it sounds it is because the white gear is worn, if so replace it.
To your question of those 2 rectangles marked in figure number 2, if you can place a little thin grease, since it is a place of friction between the metal and the plastic.