Billboard premiered it and you can read the write-up, here.
Shownu's verse comes in around the ~1:40 mark.
shownu sounds so good on the prep song! the direction on that verse is so different compared to mx's songs—and i actually like it better. yoonseok's mohae is awesome too and i'm guessing he did the guide vocal on it? leak the demo, lol, i rlly want to hear it