I bought the 42153 set yesterday and I got this green rare pin in bag 1.
How can this Technic pin be used?
I assume you mean this pin: https://www.bricklink.com/v2/catalog/catalogitem.page?P=65826
Which was first introduced in the Spike Essential set, but is currently also present in a couple of other sets, e.g. the Technic set NASCAR Next Gen Chevrolet Camaro 42153, as you mentioned but also the Volkswagen T2 Camper Van (VW Bus) 10279
Its purpose is to connect system elements with Technic elements, it serves a very similar purpose as the half pin
with the main difference being that the stud on the pin is inverted. Rather than enabling to connect a system elements with the studs away from the Technic element, with the green pin, you connect the system element with the studs toward the element.