Oh, sorry, my bad

In his readme, he says:

"Sorry for not making one layered shader
but two separated SGs.
It's easily transformed into one for using it
on only one object, but if you decide to
make two round planes with each shader
results are even better."

See what he means?

He basicly tells you to make 2 round planes, and apply the black shader to he bottom one, and the Coffee shader to the top one.

Lemme know if this helped, otherwide, I'll make it a single shader for you so that you only have to point to the Drops image, and it will work

Lemme know.