Hello
it's whistling part
put Capo on the 3-rd fret
e-3-0---0----------------------------------------------->
B-----3-----3------------------3------------------------>
G--------2p4-4-2-0-2-4-2--------4-2-0-2-4-2----3-2-0--0->
D----------------------------------------------------2-->
A------------------------------------------------------->
E------------------------------------------------------->

Take care and have
fun!