switch mode power supply - Confused about polarity of Transformer

I am confused about the Transformer dot polarity. I got design from ST's edesign Suite. Here is schematic for that :-

Now I need to order the design for transformer and the transformer design centre asking for dot polarity/Start-End point of pins. According to circuit, there are only 4 pins used on AC side and 2 pins on DC Side. The ST recommends EE-10 size Bobbin. Here is layout for that :-

What does 2 Pin in above figure donates? Is it start point or end point? Where to connect this pin in circuit?

I only need 6 pins for my circuit, but the layout for Transformer shows 10 Pins. I am also confused about the polarity.

The Transformer specs :-

Design Specs :-