fighter sharpshooter, snap shot and extra attack interaction

i was reading trough the fighter archtypes and came across the sharpshooter unearthed arcana archtype.

the level 18 trait is:

Snap Shot

Starting at 18th level, if you take the Attack action on your first turn of a combat, you can make one additional ranged weapon attack as part of that action.

at level 18 fighter you also have acces to 2 extra attacks.

how does these traits interact?

could i do:

normal attack + extra attack + extra attack + snap shot?

or is it:

normal attack + snap shot + extra attack + snap shot + extra attack + snap shot?